My size downstairs is affecting my mental health

So i (M18) have been with my girlfriend (F19) for almost two years now. Unfortunately i was not blessed downstairs. I won’t go into detail but it’s not big. She says she likes it and still loves me for me. But to be honest I hate myself a lot for it and think it looks ridiculous. Even getting changed in front of her makes me feel really really crap about it because I feel like she deserves more. It limits me wearing certain clothing items and swimming. I know, swimming out of everything. I just find it so embarrassing getting out of the water and knowing that the shorts stick to you and you get the idea.

She gives me and it so much love but I just can’t seem to believe what she’s saying about it. Am I crazy?