Hi William,
I'm sorry you are feeling so poorly right now. What your wife is doing is very cruel, no matter how irritated she might be about the situation. Calling you "psychoboy" is just as cruel and damaging as calling someone with a developmental disability a "retard" or someone in a wheelchair a "cripple" nowadays. It is not OK and this type of cruel name calling borders on abuse. It sounds like you are responding to her in a controlled, mature fashion and you deserve a lot of credit for that.
You mentioned you are working with a therapist. Do you have a pdoc? Don't let your wife discourage you from going to a pdoc. Mood swings and anxiety are very treatable, and there is a good chance you could find significant relief with medication.
It sounds like she needs to possibly go with you to a therapy session. Your therapist may be able to get through to her about how destructive she is being to you and help her understand that YES, you can get better.
Continue using your coping skills. If you need to avoid your wife for a while, that may be best (as well as you can under the same roof), just for your own health. It's so hard when the therapist says to avoid your triggers....what do you do if your triggers live with you?? I struggle with that sometimes myself.
Your garden can be your sanctuary while you try to heal.
I hope you find some relief soon.