Well well well :) My own grandmother is treating the German boyfriend of my cousin living in London the way your mother-in-law is treating you.  Many people are. They respect you for your origin and not for your personality and that`s foolish of them but no one can stop it. 
These people are troubled and don't like themselves (enough). My point is... you have no Bulgarian friends yet, you have acquaintances. You don't know any Bulgarians yet but your fiance.