I empathize. When I became A Christian, my 'friends' seemed to disappear. Then recently I was diagnosed with borderline personality disorder. I posted this truth about me and again I lost more friends. Even my stepdaughter avoids contacting me. It's seems the only people who care are a few at my church. It does hurt I know. I am reading a book called Coping with BPD by Aguirre/Galen. It's an easy read. Has categories of different symptoms and what to do. I've looked at my issues, wanting to yell at someone, wanting to leave someone, feeling abandoned to list a few.
Only thing I can think of is when you start getting these feelings of resentment, anger, bitterness, etc. try to stop or walk away. Do something that you enjoy or makes you happy when these feelings arise. A church member gave me advice on a quick prayer. I am not trying to push anything, but I TRY to say, I a low voice, "Set a guard about my mouth and door of protection about my lips. Create in me a clean heart and renew the love in my heart and the light in my soul..."
Please get better because you were put in this world for this reason. Those people who left us because of our condition is hard, but we need to get our minds of the heartache and that's the struggle. Get well soon and know I am behind you and if you ever want to talk send me a private message. I've found when I feel these negative feelings, to try to call someone who'll be there for you. It's hard especially with the social media. If I can't get an answer on my phone, I have my cat or music that lifts my spirits. God and peace be with you.