World worst mother in law

So .. Me and my boyfriend moved out just at 4 months of being together because of his Psycho mother. When we moved out she was ok, and me and my boyfriend had a bit of an argument and she got involved, telling him that he can do much better etc. Now we have made up, shes made lies up about me saying i have been to some boys house when i havent, the day she see me there apparently, i was actually with her son having tea! And now shes pretended shes collapsed to get his attention, which just to confirm she was lying again! Does anyone else have a family member of your other halfs family you just hate??