I've found that I must have something that's just for me, that just makes me happy, that I do specifically to take care of myself, before I can spend any time or energy on doing things for other people. This includes simple responsibilities as varied as meeting writing deadlines and washing my clothes.
It doesn't matter what I do for myself: it could be tending a garden, or maintaining an aquarium, or walking 3 miles a day (or 1 mile a day, or fifteen minutes) but the point is, I deserve it, it's just for me, and I refuse to feel guilty while I'm doing it. Anne does the same thing.
Once you're taking care of yourself, you can take care of other things and other people . . . and you can surprise yourself by discovering what you are really capable of doing.
You're not your job, whatever you determine it is at the moment: (Mother, Father, Husband, Wife, Crazy Cat Lady, Tony Orlando and Dawn Fan Club President, Cardboard Box Spaceship Designer, etc.) When you take care of yourself, and give yourself something that is just for you (have I made that clear?) you'll figure out rather quickly who you are and how you define yourself, because you get to know yourself again.
I've walked this road before, and I'm sure I'll walk it again. Here's the map: take it.