Just Heart broken

Ok so, I am quite young. my recent boyfriend was a little bit older then me and we were together for about 1 year and just past half.. but the other day (it was his birthday) he decided that he was going to leave, he was going to out the blue leave me and start a new life because out relationship wasn't healthy. and I totally agree that our relationship was but healthy at all. I mean we dated for a long time and we could go for months without seeing each other and because he is older and has some responsibility he was very busy at one stage and I am not aloud to say why. But of course I still love him. but I have no clue how he feels about me anymore. He threw his feelings at my face for 1 year and 8 months and all of a sudden, totally randomly I get a TEXT, saying he hates what he is about to do but he has got to leave and all this crap but I get told from my best friend the next day that he did it so easily without any emotion at all. Oh that's how I met him, threw my best friend because when he was young and without a family, her family took her in so he is technically like a brother to her. At least he was, she never wants to hear from him again after what he did to me.. May I add that about a year ago he had a one night stand with a girl he met in a bar, but I decided to try and forgive him for that since he was very much drunk and being seduced by the chick.. but I was only just starting to properly heal from that and then he goes and shatters my heart for the second time.. It sounds really pathetic after typing all this up but I really needed to get this off my chest and know that some of you girls have been through similar situations? It just hurts. People were really understanding and patient with my at first but now i am starting to hire the way I feel about it and I think people are starting to think I'm already over him, but I am do not. it's hard to still love someone, but hate them at the same time. I thought he had grown up a bit after the first time he broke me but then he does this. Our relationship may have been very unhealthy but that doesn't mean that I don't love him anymore, or that it doesn't hurt any less. all this time he kept saying to me how much he is in love with me, talking about the future, saying how beautiful I am and calling me all this shi, and he would even talk about how he would never leave, BUT HE FUCKING DID!! I don't get it😪

EDIT: Before I and found out that he cheated, he basically did the same thing saying that he fucked up but wouldn't tell me why and that he is leaving and all that.. then I found out that he had actually just cheated and hated himself for it and thought leaving was the only thing to do. And I never got the chance to say to him even though our relationship is screwed up doesn't mean u have to run away from it or can't fix it. if he really loved me he would have realized that.