Single moms, help

My husband just left me and my son. He lives 100 miles away from us now. My son is just one of those kids that is sick all the time. He has doctor appointments regularly (this week he has 3). I've been having to miss work a lot because he gets sick or gets some contagious infection from daycare or has appointments that I have to take him to... His dad is too far away to help me on a day to day basis (and I kind of resent him for doing that to me).

But lately I've had my own health problems and have been putting off going to the doctor. I already have a few thousand dollars in medical bills on my son (even with insurance) and I miss so much work already, that I feel like I dont have the time or money to take care of myself.

My parents are here, but they help me so much that I feel awful asking for anything more. I just dont know how to do this? How do I make time to take care of myself when I'm literally always worrying about taking care of my sick child on my own?