what is it going to take?

I feel like the biggest whinnie girl ever! there are so many people going through sooo much and it almost feels like bitching about my problems is wrong. ugh! but i'm only human so here it goes.
I love him so much, but it seems like I'm not making him happy I understand that he is depressed and he acknowledges the fact that he takes it out on me, but doesn't seem like he is doing anything to change that.
And when he is with his friends I more or less don't exist, he says he'll call but he doesn't, what is the point of him being with me? is it that he just doesn't want to be alone? I'm not a fricking mind reader I like being told things straight to the point, and lately every time we get into an arguement I more or less get sent out away, I'm not a relationship expert but I'm pretty sure that's not how relationships are supposed to be. I've been told to leave him so many time, I've also been told to talk things out, we talk...sorta but it almost feels like things don't change.
We are supposed to go on this big vacation in December, but I am wondering more if we are going to make it to then and on top of things I kinda feel pressure (not by him but by my friends) to book this trip but what if we are not together any more by then? I'm paying for his part as his birthday present and if I book it no one else would be able to go aside from him.
I don't know how to leave him I love him so much and no matter how upset I am at him the second I see him my world gets brighter and my heart skips beats...cheesie I know but totally true. I feel like the only way I'll be able to end this relationship and truly it have it be over is if go far far far away. I've been thinking about the Peace Corpse, have been doing my research, it all feels like it's pointing to use breaking up and I don't know how I'll be able to handle it.