Sometimes it's difficult to remember when you're caring for someone else that you still have needs yourself as an individual.
Try to make time to yourself.
In your routine try to make some ‘you time’. It could be that you just have a nice cup of tea, going for a walk, or even have lunch out but important you do something to take care of yourself.
Try to keep up with your circle of friends, make time to socialising with them. It's just as important that you look after your own emotional health, as let's face it without it you will find it hard to support anyone else.
It's important you observe your own limits and the person you're caring for is aware of this. You can only do what you can do and try not to forget this.
Take care of the basics; make sure you're eating well, sleeping well, and taking regular exercise.