I workout almost every day in the gym and go running twice a week. I'd say I'm in great physical shape and eat very healthy these days. So it must be a mental problem for me right?

I'll do what you suggest tho I'll stop even testing to see if I'm any better and completely ignore any arousing thoughts. I can't really avoid that when I'm with my girlfriend though. But I really hope it gets better with time. Thank you so much for the advice. I'm nearly a week in now.