Am I overthinking my current situation?

There is no scientific evidence of any kind of foods or elimination of them “repairing brains” and treating mental illnesses. There is none. I hope OP doesn’t start doing that with her partner instead of seeking help from trained professionals.

Of course eliminating certain foods could be good for your “gut”. If you lactose intolerant stop drinking milk. And if you have reflux, don’t eat tomatoes etc etc etc If you want regular bowel movement, eat fiber etc and eliminate eating excessive red meats. If you want healthy liver don’t eat fats and don’t drink etc etc

This is common sense. And there is enough scientific evidence re how certain foods cause problems with digestive system

But you cannot treat mental illness by food or elimination of it. It’s a quite dangerous thought and I hope no one decides to stop actual treatment and start following pseudo science