What a messs!!!

so me and my baby daddy broke up like 2 months before out son was born he was drinking everyday and we fought all the time he was neevr there for me when i was pregnant i just wanted us to be a happy family so bad thats the pretty picture i saw in my head... but January i moved out 8 months pregnant into my own apartment by myself and was just waiting for my baby boy to get here! feb.2.2012 i went into labor baby daddy came stayed with me till he was born then left us the first night he was born to go to the bar.... yes the bar.. gross right?! so after that i wanted to try and make it work so i went to his house so he could see our son but he would only see him for like 1hour and that was it time to drink again. i was just done but still again i wanted to be a family... silly right.. welll a month goes by and he tells me hes with his ex again and she starts living with him! i was so upset i didnt even know what to do. but then i started talking with my ex. weird i know. but things end up going great for me and my ex mason loves him! then he ended up buying a house and a month later me and mason move in! couldnt be happier so meanwhile baby daddy is out partying and hanging out with wayyy younger kids. ends up breaking up with his ex and she moves out.. then a 18 year only girl moves into his house! hes 27... so a little time goes by and then they break up and she moves out......and then the first ex comes back pregnant with another guys baby and then her and my baby daddy start dating again.... and alll this time hes not seeing his OWN child or anything cuz he loves to drink to much and is unstable by the sounds of all that. but iam going to be hurt if he starts fathering someone else child and not his own.... but i guess were better off without him. its just a tough thing!!! please any advice just trying to stay positive thank you