For you mom, talk to L about a guardianship. In my state that could give you (the guardian) the power to void the will. Not a hard stretch that MIL does not want anything going to XDIL. Your L should have some ideas.
I sympathize regarding friends, that just makes the loneliness that much greater. However if your friends are willing to judge you without your side of the story, they are not true friends. I don't know how large your town is but there has to be some kind of social activities you could get involved in and make new friends. You said about art that certainly could be a way to make new friends. I understand it is hard not to try and win friends over but I think that would hurt your sitch.
Hang in there my friend, each day with get a little stronger.
Me 41 W 33 M 2013 Suspect A 11/15 Confirm A 1/16 She moved out 2/14/16 Stepson 13 Stepson 16