Well bear in mind H cannot evict you so long as you keep your side of the street clean. So if you stay put he has no choice other than to stay living there with you or to move out himself. If he has an OW she will probably get tired of him living with his wife eventually.
HOWEVER it's possible if you don't have any documented income your landlord might not consider you a qualified tenant on your own, so I would really try to hustle to get an income going (or if your landlord is someone you are really tight with personally, you might let them in on what's happening - not now, but near the end - if you think they would be sympathetic to your plight. )
The car most likely depends on whose name is on the title - if it's only in his name, it's not probably something you can claim. If both your names are on it then it wouldn't be protected as an inheritance. (Note - I'm not a lawyer so check this with any lawyer you talk to).
Mediation only works if both parties can be reasonable - if he's not it may be wasted money. The ay he is bullying you, I doubt mediation would work with him.
