I hadn’t read the full thread of updates before my previous reply but now I’ve read the stuff about the food, the key, the girlfriend, the lies, the fact you don’t even know if/where he works, and the fact you don’t feel safe, this man needs to go and he needs to go straight away.
You are a vulnerable woman so you need some support. Please report to the police asap that you’re feeling unsafe and worried about a potential cuckooing situation, and explain the things he’s done, (not the minor one about using the kitchen), but definitely the hiding the key which is very dodgy behaviour. If you’re worried about him overhearing your conversation with them, you can go to your local police station tomorrow and report this. He might even be on their radar already for all you know. At the least, the police can give you some advice.
Alongside this, I think you may need to invent a friend’s son from up north who is coming to your town to work and needs the accommodation, so regrettably you need to give him immediate notice and will obviously refund his deposit as soon as he vacates.
Alternatively, do you have any male friends or family who could come round while you ask him to leave? I know you said most of your circle is up north, but is there anyone you trust who could come and help you do that?
Once he is out, you MUST get all
the locks changed, which is actually something everyone should do when they buy a new home - you never have any idea of who has retained keys to your new property over the years.
Do let us know what is happening, as I’m sure a lot of us here are feeling quite concerned at the situation. Best of luck, and please take steps to resolve this straight away by getting support and advice from the police or a trusted friend/family member.