Hello.
So here's the story. I'm 19 and my gf(she is 18) wanted to have sex, I wasn't really feeling like it, because it was my first time, but she had already done it before. So we got naked, but I couldn't get an erection, no matter what. It was just horrible, because she really wanted it, but I wasn't able to do anything. We put some of our clothes back on and we just sat there. The whole situation was just awkward, but some time later I started rubbing her vag and I got a mild erection, so we proceeded to having sex, but after some time it just got limp again and I just stimulated her with my fingers.
The deal is, that I know that I can get it hard, even if we are together, kissing, holding hands, I get a mild erection. I also get an erection from watching porn. I was kinda worried, that I'll be done in a matter of seconds, but this is even worse... Now, I've read some of other topics and as much as I understand, arousal problems are not only concerned by my body, but my mind as well and lately I was mostly depressed and my mind was boggled with all sorts of problems. May that be the case? Also I masturbate rather frequently(almost everyday) and the before we tried something, I did masturbate. I think I'm doing it too often, because nowadays I just do it mostly because I can and not because I feel the need for sexual relaxation. I'm also thinking about quitting smoking, cos that affects it as well...
So, sorry for the lengthy post and I'll be waiting for a reply of any sort, thanks!