This fetish seems really strange! I'm studying psychology at the moment. Is this fetish triggered by some kind of childhood trauma or something? Like being humiliated about your dick when you were young? Maybe you're subconsciously fetishizing the issue as an attempt to come to terms with some deeply burried feelings of low self worth?

I guess you should ask yourselves' whether the fetish makes you feel happy or depressed. It sounds like a behavioral pattern that would develop depression and anxiety complexes, rather than make you feel good about yourselves'. Perhaps it's an addiction of sorts that part of you wishes that you didn't have but you have no control over? If that is the case, you should really see a psychologist and a sex therapist to help you overcome your pattern of self abuse.

You don't necessarily have to abandon any notions that your penis size is inadequate for some partners. You could embrace the truth as you see it and enjoy feeling a sense of powerlessness, yet in a loving way, rather than in an abusive way. However, whilst that would be a much healthier sexual behavior, it might still encourage an addictive, fetishized behavioral pattern. You should ideally choose to recover from your fetish addiction entirely by reprogramming the neural pathways in your brain.

This can be done by forcing yourself to abandon all masterbation or sex that involves you fantasizing about humiliation, aswel as any porn that triggers such fantasies. Replacing such fantasies with healthier, loving fantasies, even if the're less exciting and stimulating than fantasies about humiliation at first. After a while, your brain will re-structure and develop new neural pathways and the fantasies about humiliation will start to die and the healthier fantasies that you have replaced them with will become increasingly more exciting and stimulating.

It would take several weeks, in which time the old, neural pathways triggered during humiliation fantasies would become bypassed by the new pathways developed, which would grow stronger as the old, unused pathways grew weaker. After several weeks the recovery from such an addiction would be complete and the cravings would cease, although you'd still need to make sure that you didn't fall back into old ways through habit.