Sex Addiction

When I was really young I got addicted to porn and eventually masturbation. So much so that it has completely robbed me of complete satisfaction both in the normal and sexual world. I have a girlfriend now and was able to quit porn because of it, a process is already started before being with her. I’ve been trying but I still can’t shake masturbation. It’s causing issues when we want to be intimate. Even when I am on a good streak of not doing it, I feel nothing. I feel love for her but just can’t get out of it what a normal person does. I feel like my brain is just ruined. I don’t know what to do