Saying ‘No I can’t take care of you’ and disability justice. How much is too much/not enough?

I've been reading a lot about disabled and neurodivergent care work and mutual aid recently. A lot of what I have read made me realize that, quiet without meaning to, I had been participating in care-maps, aid, and care work(see edit at end of post.)I'm a beginner in the disability justice world, and I'm eager to learn more. But the question/discussion I have is about saying 'no' to doing this care work. Just as a bit of context here, I consider myself disabled (adhd, ocd, ptsd, self-diagnosed autistic), but I do not consider myself physically sick or disabled. (This is to my knowledge and, as is with all disability, prone to change lol) When a person who is sick/disabled/ND asks for help as a form of carework, when is it okay to say no? Is prioritizing my own needs antithetical to the work of disability justice? When does my right to say 'no' become in itself an accessibility need? I'm not asking for a clear answer or anything, I just want to hear from people-especially physically disabled and chronically ill people-about your experiences and thoughts if you have any. Thank you!!! EDIT: when I say I've participated in care webs and mutual aid, I mean in an informal capacity. I've never worked in as a caregiver for money.