Sex is a competition

So I used to really enjoy sex like everyone else. But back in high school I had alot of mostly monogamous sex, I started when I was 14 and pretty much did it at least 4 times a week through senior year. I started to feel like it was a challenge to make it always better than the last time, so I started reading books on how to better, then websites, then TV shows. So now I see sex as like a personal competition, how many times can I make her...how long can I go how many spots can I hit. While it still feels good I know I'm over thinking it. People tell me I'm good and I don't even care, it's almost like a sport now more than a way to show love or lust. is it normal at all?