First I want to touch on the friend from group who you got along with for months...

People compartmentalize relationships, that friend may have only seen you as a "group friend" or you'd have exhanged contact details ages before group even ended, and had you been real friends contact would have remained long after.

Me for instance, I have friends I talk relationship, life stuff with, I have friends I only do light hearted stuff with, and I have friends I confide in regarding my bipolar and stuff... They all serve different emotional needs, all my eggs are never in one basket (it might get heavy and break) and in my experience, this is how many people navigate different relationships...

Now, all these friends of your sister's?

Stands to reason that if things went sour between you and her that her friends would remain hers (kind of like with a couple's divorce) so its not really surprizing that they're not your friends now.

And even if they pulled away from you before the Kerry incident, still kind of makes sense (atleast to me) because they're relationships she has cultivated and thus they may not feel the need to befriend you as well.

Like my brother and I are friends, we hang out together just the 2 of us quite regularly, but we only have 1 mutual friend. I get along with all of his friends like a house on fire when they visit, (you would never say its not my friends too) but I only get invited to things if HE thinks I'll enjoy it, and thus extends an invite.

They don't invite us both to their parties or whatnot. I don't think it even occurs to them to include me and that's ok, they're his friends, not mine...

You said you can't sell, are there rules against renting?

It would create an opportunity for you to move to a new location as well as provide a stable income.