Introducing myself

Hello there,
I'm 19 years old, male and about to start college. A few weeks ago, me and my gf tried to have sex for the first time. Let's just say it didn't work. So, we tried again a week later. Still no luck. After thinking through possible reasons for this, we finally figured out, that the condoms we had were too small. So, bigger condoms were bought and a third attempt was started. Still no luck, although this time the problem was rather obvious (I knew there had to be a downside to the whole big condom thing). Anyway, two days ago we tried for a fourth time. Everything seemed to go well, until I noticed something. I didn't really feel anything. Sure, it was probably a little warmer than usual and I felt closer to my gf, than ever before, but I didn't really feel any sexual pleasure. And after a few minutes I felt my erection slipping away. The next morning I starting thinking about possible causes once more. I finally came to the conclusion that my agressive masturbation over the last few years is probably to blame. So here I am. I'm not convinced I actually have a problem with porn itself, just the masturbation technique. But I'm hopeful, that not masturbating will fix my problems after a little while and not watching porn isn't going to hurt. Besides porn without masturbating seems kind of pointless to me, so PM it is.
Anyway, best of luck to all of us
See you around