Purple gave really good advice, pretty much everything I was going to say.
My boyfriend and I have been dating for 4 years, almost 5. We started dating when I was 16/he was 17. We have learned a lot about eachother and relationships with eachother. I hadn't ever had a boyfriend before him.
I have learned quite a few things about stuff I didn't realize most boys just dont quite get..
the biggest thing I realized is they try so hard to NOT hurt your feelings, they almost always DO hurt your feelings. they dont think so hard into things as we do. if I tell my boyfriend "this dinner was okay, I just didn't really like the taste" he would take it at that for face value. where as if he told me that, I would worry that I did something wrong, did he not like how I cooked something.. ect.
That was a horrible example but it's all I could think of.
He also had to learn how to read into me, so that when he wants to go do something and I say okay but I really dont want him to go even though I dont MIND if he goes... of course all I say is he can go, have fun. well he can read me, and knows that is so NOT what I mean. Bwhaha.
I would just talk with him about what's going on with you, why you are feeling this way, why you dont KNOW why your feeling this way.
a lot of the times when my boyfriend and I are fighting, it's because of me. I just get irratated so easy.. I think in part it was due to being an only child, so I really need my space sometimes. but if we are fighting and it's me causing it, I'll say sorry for being snappy, I don't really know why I am irratated. he usually will say it's okay and he usually has a guess as to why I'm irratated.

it just helps me not be so annoyed to tell him I am annoyed.
I wouldn't worry about his party. he must be a really nice guy if he didn't get mad at you for calling him a suck up. bwhahaha. =P
He probably really didnt think you wanted to go so didnt see the need to ask. it took my boyfriend a long time to realize he should still invite me (unless it's a boys night or what not) even if he thinks I wont want to go.. because it does hurt my feelings. I know where he's coming from, but it still hurts. so I can relate to you there.
And I really liked purple's advice on asking him to help you study, I think that would be nice.
I hope it all works out, when things build up like that you really just got to get them out there with him. as long as you arent screaming at him or being accusatory, then it should never turn into a huge fight. it might be a little argument, but you just have to keep talking and it will resolve. and it's okay to cry, I end up crying a lot. especially if I let it build up.