Does my boyfriend love me or use me?

I am gay, and I am in a relationship with my boyfriend for more than a year. He always says he loves me and he is very happy with me. I just recently noticed that he does not invite me to any party, unless I ask him to invite me. He did not invite me to the Christmas party, and he didnt invite me to the new year party too, which was going to be held in his friend's house. I actually told him that I wanted to go with him to the new year party, and he said OK. One, his friend was having a birthday, so he said he has to go there, he did not say anything about it untill I asked him why he does not want me to go there with him. I did not go to that party, anyway because I did not have time. Recently we were fighting and were grumpy and not talking to each other for a week. Then, i gave hima call and told him that we should meet and talk some night. he said he can't that night, because he was having a dinner party in his own house. Oh my god, it was so sad to hear he is having a party in his own house without me. I am very angry these sayd, so feel like I want to break up with him. Am I doing the right thing? what do you think? does he love me or does he use me as a "uck buddy? I know I am good looking, but sometimes think he is embarressed of me. Can it be true? does your boyfriend or girlfriend do it to you too?