My head...please help.?!

My head...please help.?

Everytime i'm around alot of people are something my head starts to shake. It also does it when I talk to girls are get angry. And when I take school pictures it also shakes as well. I need help what is this? I know it might be nerves but how can I control it? Is there any medz I can take for it? I want to go to the doctor so bad but I think the doctors doesn't know what it is.

I'm only 18 years old.

I saw someone with that. I think it means that your brain is so big that your head is sagging!! Thats what my teacher used to tell this guy Martin.