I have to say it because it's what you don't want to hear

You weren't left for no reason; you were left because you cause everyone around you strife Matty. No one wants to deal with it. You treat people like they're worthless in your little masterpiece of a manipulation and then you expect the world to give you a break? You can't get by in life on hellos and goodbyes.
It's time for you to grow up and realize that you DON'T have to repeat the pattern of your mother; that you can be a more mature and real person than you were before and one that is respected; not felt sorry for because feeling sorry will never fix your problems. It will only feed them even more and make your weakness stronger. Repeating the same pattern won't change you; it only shows how low you've dropped over the years and how pathetic your behavior is seen in the eyes of those on the outside of you. 
Stealing someone's boyfriend from them isn't right either and it comes back on you; everything bad that you do. Do you want to lose everything you have in an instant because someone runs game on what you have? NO. You've judged me for years; put me down; lied to me; manipulated your way into getting what you wanted out of me and you've pulled the same maneuvers that you've done on a lot of your enemies on me; someone you claimed to care about and have respect for. I seen that not long ago; I have to stand up for myself to prove to you that I won't be walked over and that I'm not one of those people who will feel sorry for you because I know that you have to help yourself before someone else can help you. 
I know that you had a few rough patches in life but you need to realize that you're not the only one who has had hell in their life. Everyone deals with some form of adversity at some point; so you're nothing new to that. You're closer to 30 now and you need to look outside of the drugs; the promiscuity; and the trash talk and see the person you were supposed to be. This isn't you and it shouldn't have been to begin with. Everyone has a choice to make in life. Feel horrible forever or get up and make your life better yourself; it's time you take that charge and go for the positives in life; negativity is what brought you down to the point you are at now and no one wants to hang around negative people. 
Grow up and then maybe people will stay. If not; you won't ever truly find happiness until you know that life doesn't revolve around you. You revolve around life.