Why are men so insensitive?

Nicole • Happy and contented
I've been in a relationship with my boyfriend for 3 years and I can sense that he's changed a lot. He's always too busy to see me. His reason is that he's too busy with his studies. But always makes time for his friends. I hate him. I just wish its easy to unlove someone. He thinks I'm being overreacting and too shallow.  I kept on telling him my side, and he would always tell me that he'll change for me. But always fails to. What should I do? Should I break up with him? He would always scare me that I wont find another man like him who loves me more than anyone else in this world. Am I really being too overreacting?