anybody else been through this?

my ex and i were together for almost a year. everything was great between us, we had good communication we were healthy towards one another, we loved eachother a lot. but towards the end of our relationship he started to become distant towards me, he started hanging with his friends more and started to see me less often and it bothered me and instead of being understanding like he used to, he belittled me and broke up with me. he said very mean things, that i was too negative and always looking for a reason to be mad at him but literally i saw myself becoming a second priority to him while his friends became his first. the same friends who were ignoring him when he wasn’t doing anything with his life. and it hurt even more because he’s very insecure and negative towards himself and i was always the one trying to make him feel better and shit was tough because he’s so stubborn. so hearing him call me the negative one when half the time i dealt with my own issues by myself so i didn’t burden him with that just fucking stung. and now he’s just become this cold hearted person towards me and it hurts because i didn’t do anything wrong to him. i know that sounds hard to believe but i was always open to communication and problem solving, ffs i still am open to that!!!!! but he just uses me when he needs me now and then never gives the same effort back. i’m just really hurt because when we were together and his friends didn’t influence him the way they do now, he was the sweetest person i knew. now it’s like i don’t even know him and it really sucks :/ i feel used and lied to.