1. You're not a pervert or a sexual deviant or a bad person.

2. Without more information, I'm not one to jump out and blame your preferences in porn. It could possibly be related to past incidents or an inability to be relaxed with your boyfriend. Worry, pushing things, all of those can make it hard to have an orgasm so my first thought would be to calm down, relax and let things flow. If necessary, you may want to see a therapist to work though anything that might be causing you to tense up and not release.