Is there any risk to your assets by him being in your home?
How living together without marriage impacts your position in terms of division of assets and support
Do not use fear of him retaliating as a shield against making him past rather than present. If you are having a hard time digesting the legal side by yourself, do go to a solicitor. if you can afford this leech, you can afford a short consult to put your mind at rest.
A longer consult with a gameplan to get him out of your home and the relevant authorities notified would be even better. It will save his future victims, women just like you, women who will be heartsick and hurt just like you, women who will lose money just like you.... an awful lot of heartache if immigration is forewarned and forearmed and the next time he tries this he is stymied from the onset thanks to his track record. If you can't do it for you, could you do it for them, the other women he is manipulating and lying to right now ?
Where are your friends love ?
If they have pulled away because of him, would it be within your comfort zone to reach out and reconnect, because believe me some of them will be chomping at the bit to help their friend after having had to pull back from her for the sake of their sanity.
Same goes for family.
Please take action love, hanging on him in your home won't undo the "mistake" aspect. Holding on to it is never going to make you feel better about what happened. It will never reverse time and make things be different.
You can get over and move past a mistake, even emerge stronger and with more appreciation of the person you are with the right sort of help. But first you have to make the mistake a thing of the past, not the present, smirking on your sofa deliberately kicking you and trying to push your head down, because doing so is to his advantage. If he can destroy your self esteem and self respect further it bode well for him getting your co operation and support for as long as he needs it.
What he is doing to you in terms of belittling and wounding is no accident. It is a callous, calculated action in order to knock your defenses out and have you come to rely on him for any small crumbs of comfort, to help you deal with your isolation and your soon to be fully warped sense of worth.
Know that love, know that every time he goes to draw blood sentiment-wise he is doing on purpose to reduce you, so he can get what he wants. You need to get him away from you, for good.
He is an emotional and financial vampire, get yourself some garlic (in the form of a lawyer?), holy water (in the form of firends\family?) and stake the bastard.