When will I return to normal? (PIED)

Some background: I'm 18 yo and have been fapping to porn for the last 6 or 7 years and have only recently found out it was a problem (multiple tabs, different genres). I haven't had a girlfriend in about 4 years so I've never had a "real" relationship until now. I am very attracted to my current girfriend and have true feelings towards her, but I just couldnt get it up the first time. I thought it was normal since it was both our first time having sex at all. The second try was in my car and eventually I did become hard enough to have sex, but it just became weak after a few minutes. We tried 3 more times after that, but it just wasn't happening, and she began to blame herself. After that we decided to not try for a while and just focus on us instead of sex. I told her it was because of all the porn I watched and she was understanding. My question is: when will I become normal again? I quit porn 3-4 weeks ago in an attempt to stop this from happening ever again, and I've had no problem getting rid of the porn. I've only had thoughts about real sex with my girlfriend and some urges to masturbate. Some things I've noticed is my morning wood is stupidly hard now, dirty thoughts have gone away, I'm much more productive, and have gained more confidence when speaking with strangers. I also had no problem getting erections thinking of my girlfriend. The one thing I am unsure of is if masturbating for sensation is bad when going through recovery (btw, the orgasm for pure sensation was much better with just masturbation compared to with porn). l'm worried that I won't be able to get it up when we finally do try again, and that'll destroy me. Thats basically it but I'll list all of my questions: Is just being around my girlfriend helpful for rewiring? Should I masturbate? How long would it take for me to become normal again? Am I normal yet? Could exercise help?