I'm thinking of keeping a blacklist of my friends
What is the purpose of making a blacklist?
I'll need to keep a list of enemies as well, honestly I don't have many friends who don't want to do what they can to harm me.
While it's good to be cautious of the people closest to you, it's very paranoid and harmful to not trust anyone and think they'll do the worst to you. If they find out, then yes they'll think badly of you. Trust them so they can trust you.
They aren't my friends anyway then. I know who my true friends are and that they like me for me.
I'm sorry you are feeling that way and have these feelings about people. It's wrong and unhealthy to have these dark thoughts towards the people closest to you. You might want to try and trust people more or talk to someone about how you feel.