"His friends are bad influences too ive never liked them and they all either cheat on their girlfriends or are hunting for girls."
To fall back on the old saying - 'a man is known by the company that he keeps'. Or the snappier 'birds of a feather flock together'. They all cheat on their girlfriends? So does he. They all hunt for girls? So does he. They are no more a bad influence on him than he is on them. There's a reason they're his friends, and he is theirs - they want the same things.
"I dont know how id ever trust him again."
Why on earth would you trust him? He's a liar and a cheat. Not worthy of your trust again. Ever.
"All ive had is shit relationships and this one was the best out of a bad bunch."
Unfortunately, having being in a shit relationship makes you vulnerable to entering other shit relationships. It desensitises you to poor behaviour so that you accept it. And the sort of men who revel in their poor behaviour - abusers - are able to pick up on that. Yes, your boyfriend is an abuser, his behaviour is abusive. He cheats on you and "he keeps saying she's lying and trying to make me feel crazy" - that's abuse. So, he's a cheating lying abuser with a serious problem with alcohol. GET RID!
"The thought of starting ahsin and being alone terrifies me."
Honestly? You need to not be in a relationship for a while. You need to step back awhile and work on yourself. Learn what boundaries you need to have, and how to put them in place. Read up on Shark Cage Theory, consider doing The Freedom Programme, it's available online.
Silver lining - "My partner of 1 year" - you've only spent a year with this loser, so he hasn't wasted too much of your time. But you need to get him out of your life, out of your son's life, and you need to stay away from relationships until your head is in the right place and you can protect yourself and your son from abusers.