my relationship

Newbie here!

My girlfriend and I have been together for 6 months, tomorrow. I've never had a girlfriend and she has never had a steady guy (over 2 weeks) so pretty much it is the first serious relationship for both of us. We know each other pretty well and love each other.

A problem I have been having is that I just get really upset and jealous. I know she loves me and she always tells me I'm the "best guy she's ever met." But for some reason I always feel insecure like she could either be interested in other guys or willing to leave me after the school year (i'll be graduating she still has 2 years left).

What is strange is I still have these feelings even though she tells me she doesn't want me to graduate and doesn't know what she'll do after I'm gone. I just feel that she is naive and she can change rather quickly because she is so young.

I, personally have had no experience with girls whatsoever (just one kiss on the lip of ONE girl before my girlfriend). She, however, has kissed a lot of guys and before she met me she would drink and party and hook up with her "friends" at the time. This really pissed me off when I heard it even though I had no reason to because I wasn't in her life at that time.

I get jealous when she talks to these "friends" and I don't know what to do. Sometimes I'm really happy when I'm with her sometimes I get really down.

Sorry for the long post.

I'm just struggling with this Tweet