When you fly on an airplane, the pre-flight safety presentation never fails to mention that you should first take care of yourself, and then others in case that oxygen mask drops down before you and the cabin suddenly feels cold and windy. "Take care of yourself, then others" is good advice at 35,000 feet -- and everywhere else as well.
It's not a matter of deserving time to yourself when you take on the role of caregiver, even though you do. The fact is, you need a regular opportunity to renew, refresh and reclaim some part of your life, a part that's all your own, whether it's a few days a week or even just half an hour a day.
Try to get daily exercise or even just get outside for half an hour a few times a week and move around. You don't have to belong to a gym: Get some sunshine if you can, take a walk or do whatever you can to get your blood flowing.
If you normally attend religious services (or are interested in doing so), see if you can arrange for someone to watch your loved one while you attend service.
It takes effort to take care of yourself, but it's worth it. Your continued well-being is an integral part of your loved one's long-term care plan. Remember: the decision to care for yourself isn't just for your own sake -- your loved one needs you to be at your best.