I need to break up with my boyfriend, im just not happy in the relationship?

I do love him im just not in love with him we had been together for about 2 1/2 years and we decided to give it another shot, i didnt want to i told him we are different people now and its not going to be the same but he insisted so i decided ok well who knows he deserves a chance to prove himself. But im just not happy, he started drinking alot more, and when he drinks hes a ahole.. gets extremly aggresive, would rather be with his friends, i work a 8-5 job when i come home i wld like to spnd time with him but his excuse is i spent time with u yesterday. im like what did we do and hes like well i was here when u were cooking...yea and then he left with his friends.. I HATE IT.i left (my best friend) to give my ex another shot..we've been together for 3 months now, things were good for the 1st month we moved intogether..n ever since then its just gone down hill, and i want out.i cant take it anymore.im frustrated emotionally, physically, ually.and im just tired of trying to fix this