I get wet dreams and morning wood but cant get erections due to mental stimulation?

Too much pressure: Sounds to me like you are putting to much pressure on yourself, and that usually has the opposite effect on what you want . The fact that you have wet dreams and erections indicates everything is physically working - that's great news. You may one of those exquisite people whose body wants an emotional relationship to achieve sexual arousal - you're the wondrous type where a picture just won't do!