just recently (last 4 days or so) the head of my penis has started hurting right after ejaculation, lasting up to a few hours, each day or each time i ejaculate it gets worse, i haven't really been doing it any more than in the past and i thought it was nothin, but it really hurt today and i noticed it got red-ish too. the part thats hurting and getting red is the direct left and direct right side of the hole at the tip, it especially hurts when im walking and it brushed up against my boxers and when im drying off in the shower aswell, does anyone know what the problem is / could be? thanks