I recently broke up with my girlfriend of 1 year. This was my first serious relationship, and before her, I had only slept with a few people. It was an intense relationship, so it's taken me a bit of time, but I'm getting back out there now.

I met a girl on Tinder, and we had a great first date. I was very confident, and it was clear from the start that she was into me. A week later (today), I invited her over to my place, and after a shit test or two, she accepted. Things were going well, but even after we played around for a while, I realized that I couldn't get hard. I had masturbated before she came over, so at first I attributed the problem to this. Still, something like this had never happened to me before. I kept my calm and confident demeanor and put on some porn. Finally, I got an erection, but then, the next problem started. As I struggled to get inside her, she told me that the head was just too big. Another problem I've never had before - my penis is definitely average in size. And then, third problem. Even though a few minutes before I had barely been able to get hard, now I could feel that I was going to come super quickly. And a minute later, I did.

I got the girl out of my apartment without showing any visible embarrassment, but now I don't know what to do. I had sex with 1 person for so long, and I think "getting out of my routine" is what made today so awkward. How can I stop this from happening again?