You keep talking about how your "brain isn't producing the right chemicals" & there being a "chemical imbalance in your brain". Quit telling yourself there's something wrong with you. There isn't. You said that you're self diagnosed, so you're just lying to yourself by believing these things. You're setting yourself up for defeat by thinking this way, by convincing yourself that there is something so severely broken inside that it can't be fixed without outside help. You ever heard of 'self fulfilling prohecy'? It sounds like that may be happening here. Also, you're not doing yourself any favors by being fixated on trying to be normal. No one's normal. Normal is fucking boring anyway, you can do better than that. All I'm trying to say is you probably have more influence over your anxiety & stutter than you think. They feed off of each other, the worse one gets, the worse the other will get. If you can figure out how to improve how you handle either your anxiety or your stutter, I promise you the other will improve as well.