Emotional and mental abuse

So I've been with a guy since February 2015. Although he never gave me any commitment till date, we've always been together like a couple; its just that we've never been official.I have given this boy everything I could.But since last July, I've only been depressed and emotionally unstable because he just kept playing around with my feelings and emotions and took my love for granted to another level.He also has a girlfriend since last 7 yrs who went through a heart transplant surgery 4-5 yrs back but he says he wants to break up with her but due to her family issues, he's not able to do so.I even accepted him with all that.We've done everything that a couple does! We've had fights in between where he tried to end everything but then after a while we used to sort it out and get back together.10 days back I actually found out that he was two-timing me with another girl and I've directly spoken to that girl so its confirmed news. All his friends told me to leave him but from what I saw, I thought my love would somehow change him and one day instead of tears, I would also get some love from him.Also, I've been in depression last year for 3 months (july-september).Before I caught his two timing scene, he messaged me saying that he wants to end everything at 2 am out of nowhere. I was in a complete state of shock and I cried and called him and he had no valid reason for that message.I said I'm not gonna go home the entire night since I was just crying and in complete shock! So he spoke to me the entire night on the phone, said I love you, you're mine, girlfriend etc (I have the call recording), came to meet me the next day, it was all normal again...then I found out about his two timing thing and ended everything with him.Now when his friends tell him that dude she really loved you and what you did to her was wrong, he says 'she was just a pile on, she loved me, I never loved her, she was the one behind me, I told her long back that it was just time pass!'. Blocking me and unblocking me on WhatsApp.He has just been disturbing me mentally way too much since last year and now he's going around insulting me and putting all the blame on me when all of us know what the truth was! I have screenshots, recordings, everything! So he has been playing around with that 7 yr girlfriend, me since last yr, that other girl he cheated on me with and now I guess there's a new one too! We have the same group and we chill at the same spot and all his friends know how he is and what he does. Its just that I was avoiding it all this while. He couldn't even respect and appreciate my love for him and everything that I did for him. I feel like piece of shit right now. Its like all my self esteem, self respect, confidence everything is gone completely and I feel disgusting! I am blank and I have no idea what to do because he has no shame whatsoever.