I have been in a similar situation to yourself when I ran away from my ex nearly 11 years ago. To be straight up, my first thought on reading what has happened to you was
"omg, she hasn't ended up with *my ex's name" has she? ".
First,to deal with the way you are feeling, absolutely go to your GP straight away. This would also help create a bit of supporting evidence that you aren't just blagging the DWP and there are serious real issues behind the report and situation with your benefits.
Now comes the info for how you can get help with the whole situation. I'm about to give a few things I think may be places to help. Please , I don't want to overwhelm you with stuff , they are just contacts you may wish to try. I wish I could give you guarantees that they can definitely help, but unfortunately it's a case of finding out who can help with your specific situation.
Women's aid has a 24/7 helpline that can give you real advice on how to get through this and also deal with the fear of him coming back at you. Their number is free : 0800 027 1234
Their website :
www.scottishwomensaid.org.uk
Citizen's advice - although you could call them, the best way with them is to go and see them. They will have someone sit with you and work through what is happening with regards to the DWP and be able to assist you with things we may not have thought of. Sometimes it's a good thing to have someone who isn't emotionally connected to logically go through the steps to sorting this out and supporting you. They would also be able to give advice on the next thing I suggest as an option.
Free legal advice - It may be possible for you to go and see a solicitor who would be able to advise on the legal steps you need to protect yourself from the legal nightmare you have been pushed into, and how to frame the case to the DWP. Some solicitors do a "first appointment is free" arrangement and you may qualify for legal aid if this becomes a court issue , which I'm not too sure it will as long as you can clearly outline the situation to the DWP. They also may be able to help with protecting yourself from further abuse from this man.
When I was getting court summons etc because my ex had claimed a load of benefits in my name, I went to my MP. They managed to intervene and effectively get my name taken out of the mix. My ex ended up in court on his own. I never found out what happened with that but my side of it was sorted.
See if you can get anyone to come with you , a friend or a representative from women's aid etc, when you go to your interview with the DWP. It will not only give you some support but they may be able to mention things that you might forget to say in the panic of being there. I absolutely know how terrifying that summons to go and explain yourself is and they threaten the court and sanctions etc to make sure you turn up. Very rarely does it get that far. I've had people report me for benefit fraud who have been abusers I've pissed off. When I went in to the interview, I just told them absolutely everything about the situation. I work on the premise of tell it all openly and honestly , even things they might not need to hear. They will know you aren't trying to hide anything or lie because just letting it pour out will let them see you aren't trying to make anything up just to get out of the situation. Tell them your state of mind then, and now. If you are on any antidepressants etc, take it with you so you can show them just how affected you are by this man AND by the benefits mess that is now happening. Tell them what he did to you and how you were under duress and fear. You may be surprised by how they respond. I know I was surprised, they went from being all judgemental to showing compassion and some understanding.
Please look after yourself, and I hope what I have said may help you, even if just a small amount.