I haven't really thought anything of it until now, but falling asleep at school is now worrying me?

I doubt that you have Infectious Mononucleosis ("kissing disease") from the way you describe your symptoms. But since you are seeing a doctor in the near future you might want to voice your concerns to him/her. Inf. Mono is usually diagnosed from the doctors physical exam and also from the results of a peripheral blood test (no big deal).