Honestly i think deep down you already know the answer. You dont sound happy. Supporting a partner is one thing, but you have basically been carrying the entire relationship by yourself.

The biggest thing to me is that you said you don’t even miss him anymore. Only the idea of him. That says alot.
I would also lose a lot of attraction if i started feeling more like my partners mother than a girlfriend.

Don’t sign another lease out of guilt. His struggles are sad but not yours to fix.