I am 13 and I think I might have an STD (omg please read...O_O)?

I had with a girl when I was 11. We had been doing that kind of stuff for a long time. But a few weeks after we actually had , I noticed these weird white bumps above my . Later, they disappeared and then reappeared about a month later. I'm not really sure... And now there is a white looking rash beside my . I don't really know how to explain it... When I spread it out they look like tiny white bumps. The ones above my look like just white bumps medium smallish...I've looked at different pictures of ...and some of the pictures looked like what mine looks like. I don't really know what to do... I read you can see it on the back of your tongue sometimes, and there are bumps all over the back of my tongue... They aren't humongous, they're just kinda small but pretty bumpy if that makes since... Well, what could this be? (she did screw me and she might have had some sort of sore in her mouth. i don't know. i'd ask her but she probably wouldn't remember...)