Listen up love.
6m in and this guy is A BOYFRIEND, not a Partner, and much less a DP.
It wouldn't matter if your last DP was Vlad the Impaler, you are placing yourself at HUGE risk by hooking up (and that is literally all you have had time to do) with a new bloke. You are using this guy psychologically to get away from the other bad man. But you have no idea - really - if this man is not a bad man either.
You know that it takes between 18m and 2 years for an abuser to start to show their true colours and yet just to get away from a known abuser you're going to potentially hand yourself gift wrapped on a plate to a new bloke, you barely know, in a place you know no-one except him. You are a sitting duck for another abusive relationship.
You need to go on the Freedom Programme. You need to work REALLY hard to work out WHY you got into this in the first place. We victims don't just get snatched into these abusive dynamics, we are GROWN for them, we are targetted as weakened by our upbringings and then we are sucked in. Others withhealthy family dynamics KNOW that these abusers are bad news and dump them. We have such little self esteem for whatever reason that we don't. You need to understand what happened to you to make you think that this bad man was worth having a kid with, worth being with, when clearly anyone with a healthy perspective would see straight though him.
You will make an excuse as not being able to afford to live alone. That is bollocks. This country will help you set up again, but you have to put the effort into your own freedom. By shacking up with a strange bloke hundreds of miles away, you are selling yourself into modern day slavery. What would happen if it all went tits up when you are there? Who on earth would help you?
You need to be alone, you need to recover, grieve the loss of the relationship you had with your Ex and you need to LEARN shit loads to stop it happening again. You have done NOTHING at all to protect yourself. You have potentially even placed your own son in HUGE danger.
You can't allow your DS to come into contact with a guy that you are seeing in less than a year. seriously. Sex offenders DO target single mums to get at the children. you HAVE to acknowledge that? Honestly.
I'm sorry you have chosen to think that the comments here have been hurtful, when really they are not. Your outlook is naive, your behaviour reckless. You are playing russian roulette with your lives.
If your Ex has threatened YOU, then you go to the police. If your son has been exposed to witnessing abuse, you need to get it reported, and control orders put in place to protect your son. Contact WA, contact Refuge, the CAB, every one and every one to get proper advice.
For a start. You can insist that your ExP only sees his son in a contact centre. Supervised visits too.
DO NOT MOVE IN WITH THIS BOYFRIEND.