When i have to pee really bad my dick gets smaller and literally shrinks, but once im done it goes back to normal, is that normal?
Sounds normal,probably just because your bathroom is cold,or something to that nature,but if it hurts when you pee,you should probably see a doctor.
I think this is an effect of stress. When we are stressed the body withdraws blood from areas where it isn't needed immediately, so it can supply blood to muscles for fight or flight. You may notice that when you are frightened or nervous the same thing happens.