Make it a rule never to apologize unless you truly, truly have said something horrible or hurt somebody. I have learned that and I get more respect, believe it or not. Some people take apologizing as a weakness. You have nothing to be sorry for, frankly. And if she keeps making you feel as if she is treating you differently because of your illness, tell her. If that doesn't work, go to the higher bosses. Also., email is trouble for us bipolars. I've sent more than one email I regretted. Try to talk in person instead. Hope this helps.