Drooling

I drool every time I sleep. It's very embarrassing. My friends used to make fun off it behind my back... Some friends I have.. I know! My ex boyfriend had no problem with it while we were dating... He'd wipe it for me if need be. I used to drool all over him and he'll only tease me so I don't feel bad about it. I used to think it was only something that happened to kids. Even if I did, it should be just a little bit right? And it shouldn't be all the time, right? I'm 24 years and I drool too much. please I wanna know... Is it normal? Is there some medical condition related to it? Is there some meds I should be taking??