flyboi

I have been dating this girl for about 9 months and she is NOT affectionate anymore. I am leaving for college in late August and we have decided to stay together. My goal is to try to come home once a month to visit her.
Recently, I've noticed a change in our relationship. She is just not affectionate. She does not go out of her way to kiss me, hug me, hold my hand, bla bla bla. She tells me she loves me, but she does not show it at all.
I am "--" this close to breaking it off, simply because sticking through college is huge. I need to know if its going to be worth it, ya kno? She can be the sweetest and funniest person to be around. And I love being around her. Its just felt uncomfortable to be around her when I get that sense that she doesn't want to be around me. As you guys and girls may know...it hurts. I have kind of been a doormatt lately because i dont want her to forget about me. And i do love her. I cant say i love her because of "_____", but love is crazy, and its there.
I can tell that she is holding back from me. It may be because she doesnt want to get too attached before i leave.
I don't know how to talk to her, or initiate a convorsation about this topic with her. It feels like every time i try to bring this up she is just passive and says "sorry" but very quickly and not meaningfully. I dont want her to say sorry, i just want her to appreciate me. I recently helped her paint her whole house and there was lack of appreciation there. I also drive about 30-40 minutes every time i see her plus the drive back (and gas aint cheap lol). She just doesnt seem like she puts in an equal amount of energy into this relationship.
Any help would be nice. Thanks!!