Ok so I’m 22 years old and started having sex at about 19. I have been with a few women and never had a complaint. I use to be able to have sex for a very long time and very vigorous as well. About the past 8 months to a year I have been single and haven’t had sex. Recently I got in a long distance relationship and started doing kegels and masturbating to prepare myself for when we got to see each other. Everything seemed to be going well until I had sex with her. I guess you could call it premature ejaculation, but everything just feels so sensitive. I was reading around a little and saw a lot of people say it can happen if you’re nervous, but I wasn’t nervous around her at all. What use to be probably an hour plus is now 10-15mins and that was at a slow pace, if I got a little rough I felt like I was going to explode. In one of our sessions I pulled out to rest for a sec and all of a sudden I just ejaculated while not expecting it. After I went back home and continued to masturbate, lately I have only been lasting like 1-2mins before I can’t take it anymore. Masturbation was fine before I had sex with her that’s why I’m wondering if there’s some recent factor that could be the problem. I would really like to get to the bottom of why I’m not lasting very long. I’m not sure if there’s something causing this problem, but these are the only things I can think of:

1) A little before the 8 months to a year of not having sex I had a Hernia surgery close to my groin area, I didn’t know if there could have been some nerve damage or something that could of went wrong down there.
2) Recently I had a lifestyle change and have been going to the gym a lot and taking a few supplements. Maybe I could be overworking myself at the gym or possible it may be my diet change? The supplements I take are multivitamins, protein shakes, and Creatine. I thought it was the creatine so I have stopped taking it for about 3 weeks now and haven’t noticed a difference.
3) Last, the only simple thing I can think of is that I just haven’t had sex in so long that I have to relearn/get use to doing it again.

Any idea if these are contributing to the problem or if there is anything else that could possible be? Thanks for any help its much appreciated.