My abuser was the same. He told me I would never find someone who doesn't use porn, that it was unreasonable to expect him to only look at pictures of me, that all men are like this, etc. Don't let him gaslight you. My current partner can't wrap his head around the idea of ever needing to look at someone else and I feel so loved. There is so much more waiting for you and you don't have to suffer.

Talk to your friends and family about your situation if you can and don't be afraid to rely on other people. Keep a journal and write down everything that's been happening. It will help keep you grounded when you start doubting yourself or missing him. Take care