Penis irritation due to urinary infection?

This all started about two weeks ago... I drank about half a gallon of stuff before I went to bed, mostly Gatorade and tea, and when I woke up in the morning, I had to pee really bad (naturally, lol). So I stumbled to the bathroom and assumed the early morning pee position, ya know, one arm on the wall behind the toilet, the other making sure my aim is good... and I had to pee for a LONG time, and I was losing my balance so I decided to kinda put a little more force into it to move things along a bit better. The next day, I noticed that it hurt a little when I pee. There's really no other symptoms other than a little irritation inside my penis. No discharge or anything like that. I don't think that maybe I have an STD and didn't notice til now cause I've only been with one girl and I use protection every time.

Or maybe I just have a urinary infection. Do guys get those? I know my sister used to get them...