Discuss it with your doc. He can further reduce your hours. If your employer than can no longer accommodate you, then it's over.

If your doc thinks you should not be working than apply for state disability while waiting for the appeal.

The Appeals Council might deny you, give you a favorable decision, or they might remand your case. Can you hold out a few more years? State Disability will give you a year of benefits while you wait most likely (if your doc agrees.) A new application might be quicker, but you'd lose the backpay.

It is really unfortunate you can no longer do both. Many will be forced into making tough choices about giving up backpay for need of a faster recourse. With your lower income, you might want to consider searching out other resources as well. Can you move in with family for a few years? Add a roomate? Get foodstamps? Etc.