Long story short...I need advice...

Okay so I'm 17 and I've been with my boyfriend for a year and 3 months and for the past couple months things have changed between us dramatically and I'm not quite sure how I feel anymore. Lately I have to fight for his attention, I ask for him to come over and he says he's too busy so I'll compromise and go over there and find out he's got friends over or that he wasn't actually busy. He never texts me like he used to and it's always take take take with him.. I never feel like I get out what I put in. I used to feel so sure it was him and now I'm scared it's not.. what do I do? I'm sick of feeling guilty for not even being able to be around him for how he makes me feel when I'm the one compromising..