I'm sure your mom will be fine if the cleaning doesn't get done. I'm assuming they can feed themselves. If not, they'll need to make arrangements for that. You do no one any service by staying. It's not like you are cutting them off from you or disowning them. You have to take care of yourself before you can take care of others. If they complain, just say "I'm sure you'll be fine" and mean it. Have confidence in your parents to take care of themselves. You are in poor health. You owe it to your family to do what is right to get yourself back on track.
I'm sorry for your difficult upbringing. People don't realize how much that kind of pain keeps hurting. If you broke your leg, no one would take your crutches and say if you don't walk on it you'll never get better. They let you heal first. But emotional wounds are not respected in the same way even though they can be more dibilitating.
Big hug. I'm sure you'll do the right thing. Only you know all the details of your decision.