Wildrose, your life matters too. Giving good things to yourself is what healthy people do, in order to stay healthy and happy.
As Zoso said, learn to say No. It's not easy , but it's your right to respect and care for yourself, and not give your all away to others who drain you dry.
I am glad you are here. Melody Beatties book 'Codependent No More" is about learning to take care of yourself, and to live the best life you can. how not to be used, and how not to feel responsible for fixing everyone.
big hugs to you. a day at a time, do what is right for you, even if it doesn't feel great at first, it will give you back yourself, and eventually it will feel really really good.
keep posting, we care.
chicory