What do you mean by chiro adjustment that slipped ?

"because I still have not pinpointed what caused my setback that made me worse off than I was even before I hit my head. "

You will never fully understand PCS. You will likely never know what caused your setback. Sometimes, we can connect triggers to symptoms but that usually means the trigger and symptoms are repeatable. One time setbacks are almost impossible to understand.

It appear you have not got your anxiety under control. A continuing compulsion to understand is symptom of your continuing anxiety.

One thing you need to avoid is quite simple. If a chiro or doctor or functional neurologist says "I can fix that" or " All you need to do is ....." , Do not believe them. There are no such fixes. I can tell you that resolving anxiety will be a big step toward resolving the other symptoms but still not a fix.