Cant Ejaculate

Patient: Im 18, you think I’d have trouble keeping myself from ejaculating all the time, but I can’t ejaculate. I mean, I am physically capable, I know this because I have before, but I just cant seem to orgasm when I masterbate no matter how hard I try. I have to wait until I get lucky in my dreams for it to happen. I have no problem getting an erection. I am not sexually active. I have some rough hands, and it is very hard for me to get excited and horny, but I dont know if this is a mental problem, or a lack of enticing chemicals in my body or if I just need to find somebody with a softer touch if you know what Im saying…whats your opinion?