XOXO

WOW

I have got to say that your FMIL takes the cake for ultimate b-t-h. What nerve!

I think you need to talk to your FI and tell him that you guys have to do something. You are going to end up having a nervous breakdown. I understand that he does'nt want to rent. I can totally relate but is it worth your sanity???

Sorry to hear of your stress. Sounds like your FMIL is a little off. Since I was almost in a situation like this at one time I know how really crazy the mother of your significant other can be so my suggestion is to get far far far away! Very far away!

Seriously though it is a tough situation because she is his mother, and putting him in the middle even though she is a psycho will cause a huge strain on your relationship because no matter what 'She is his mother' It is important he knows what is happening but it is wise to proceed with caution. You never know if he will resent you for things said in a rage.
You need his support but you can not make him choose. For the sake of your relationship together you need to either get your own place or move elsewhere until you can live together peacefully. Best of Luck. !!