All of these factors affect your mental state and your health. I did not live with my mother, for several reasons, but if you live with your family member, your mental and physical health may be even more compromised.
Get support. Find a support group in your area, take a class, find a counsellor. I spent two or three months seeing an Elder Services counsellor with Mental Health, for "caregiver support." Being an adult child caring for a parent brings up many issues. You may have buried resentment or frustration, or issues unrelated directly to your parent, but being in this situation brings them to the fore. Seek help if you need it. If all else fails, try keeping a diary where you write or type out what you're feeling and thinking.
If you have a friend who's been through this, talk to them. There are support groups online if you can't get out. In my community, there was even a caregivers support group held in the afternoon, because many caregivers have to be at home in the evening.
Talk to your own doctor about your situation. Being a caregiver is a significant health risk and your health care provider needs to know that.
You need to do whatever it takes to be healthy, for your own sake and for your parent's sake. And ideally, you want to survive this and go on to have a healthy and happy life.
Make a point of thinking about what you eat. The temptation is to eat comfort food, junk food, fast-food. Every day seems like a crisis, like there's never any time to plan, and it all blurs together. But this is not a temporary crisis, this is your life, and you need to be properly nourished. If food is not your thing, ask a friend who likes to cook for help planning meals. Lay in supplies of easy to prepare foods, healthy snacks and so on. Try to plan the food in your house so you aren't tempted to eat stupid stuff. Your community also probably has resources such as Meals on Wheels. Take advantage of this. Meals are offered at cost and delivered by volunteers. Your parent will certainly qualify, and as a caregiver, you will also. You may even find that your parent's meals can be paid for or subsidized by programs such as Veterans affairs. Research the take-out places or food-for-delivery places that offer nutritious tasty food, and keep those numbers handy. Make eating properly a priority.
Get enough sleep. You are not strong enough to act as a caregiver AND go without sleep. No, really. Sleep is not just for sissies, it's how you recover from your day and how your body restores itself. If you have persistent sleep problems, talk to your doctor. Any health issues you already have will be seriously affected by lack of quality sleep. Take drugs if you need to. You may be depressed or anxious during this time, even if you aren't normally.
If you drink alcohol or use drugs in a recreational way, be aware of the temptation to resort to this. Use mood-altering substances with respect. I would sometimes have a one or two drinks, never more, if I'd had a particularly aggravating day, but I didn't keep easy-to-drink alcohol in the house as a rule for the entire time I acted as a caregiver for my mother. Getting blotto or being hungover is not going to help you cope, no matter how tempting it may seem to step into an altered reality. Find other ways of coping, at least until this is over.
Exercise is a good thing, even just a walk around the block. You may try calming practises, such as yoga, or meditation, but you may also find that these make you more anxious. Some people need to be even more physical than they might normally be, to get rid of frustration and pent-up energy.
If you belong to a church or spiritual community, this may be a good place to turn. Ritual can be calming and reassuring. You may want answers and talking to a minister or priest or other spiritual advisor may be beneficial. If your own spiritual advisor is not trained in pastoral counselling, they may be able to refer you to someone who is.
Find hobbies you can use as distraction. This might be knitting or other crafts, computer games, crossword puzzles. I found that watching TV was the worst thing for me, because it was passive. I needed to be more actively involved in order to stay focussed. Colouring books might be good, or doing sports. You may need to find things you can do alone, because your schedule no longer matches that of your friends. But if you can find time to play cards or other games or activities with friends, go out dancing, go for walks, this will go a long way toward keeping you sane and focussed.
Sense of humour is key! Seek out funny movies to watch, funny books, anything that can lighten your mood. Find ways to laugh with your parent. Laugh at yourself.
It's easy to say, "take time for yourself," but incredibly hard to do that when your parent has needs. With dementia, any small thing can become a crisis, because the person no longer has the ability to cope or to find an emotional balance. You have to become the problem solver and figure out what's upsetting them, how to calm them down, and how to fix the problem. Doing this all the time can become exhausting. If you are also providing physical care, doing housework, paying bills, your life can be completely taken over by this role. Even if your parent gets care from others or is in a care facility, there's rarely a moment in the day when you're not thinking about them, worried about various issues you are now responsible for.
I had no other family obligations when my mother needed me. You may be balancing the needs of children, spouse, siblings and other family members, with the needs of your elderly family member. There's the criticism that can come from friends and family, the well-meaning advice, the suggestions, the remarks they make after a visit where they saw "nothing wrong," and wonder why you feel the need to have your parent in care. And then there are the people who can't help but see your situation through their own needs and emotions, of their fears or sense of guilt about their own parents.
You need to find out how to protect your parent in the event of incapacity, such as an Enduring Power of Attorney for yourself, a Representation Agreement for you to make medical decisions for your parent, an Advance Care directive or plan so you aren't faced with making mind-boggling decisions about end-of-life issues when you're in a crisis state. You also need to consider financial planning, for your parent and for yourself. And face the fact that you may die or become incapacitated before your parent dies, and make a two-tier plan to care for your parent if you're no longer able.
You also need to be aware of the perceptions of others, and that caregivers may be suspected of taking advantage or abusing their elder. Keep accurate records, keep receipts, don't mingle your money with theirs. Even if you have to place their groceries on the conveyor separately from yours or write two cheques, keep their affairs separate from yours as much as humanly possible, so you can show the details if there is ever a question.
I cannot provide advice on dealing with difficult family members, but this is very much a problem for many caregivers. You are not alone in this. It's particularly prevalent when some family members live far away and aren't seeing the elder frequently. They may talk to the elder on the phone and hear the complaints and excuses, they may only see the parent when they're on their best behaviour during a visit and they may assume they know more than the people who are handling things daily. This is so common, it has a name, the Sister from Saskatchewan or the Sister from Seattle.
The number one tip I can pass along is that you are not alone in this. Many people have walked this road before you, or are walking it right now. If someone in your family has dementia, recognize that it's a physical illness, not a mental illness, not a character flaw, not an indictment of your family. It's not your fault. You didn't bring this on yourself or wish for it or somehow enable your parent into being this way. It's an illness, like cancer or pneumonia. Tell everyone you know, everyone you deal with, from the banker to the plumber to your friends and co-workers. Sometimes you need time away from that set of problems and you dont want everyone to know, but you'll find that most people are very sympathetic, and may even offer advice or solutions you may not have thought about. You may find that friends have been through this or are going through this, and that you already have a support group or network in place that you weren't aware of, until you needed it.
The Alzheimer Society has some excellent resources, including support groups, classes for caregivers, online classes and groups, and plenty of articles and information online. Google them for information specific to where you live.
I'll add links to pages with information and resources in coming days.