You have lost me about the unsuccessful thinking issue. I know what it means to struggle to think. Accessing memory. word finding. calculating, processing thought, understanding spoken words, spacial relationships, math, imagining, imaging, recognizing facial expressions, etc. None of this sounds like what you describe.

What kind of work did you do ?

You sound like you have a psychology background, at least to me.

Your explanation of interactions sure sound like what I went through back in 1982-3. The depression that was diagnosed was not the morbid, I feel worthless, suicidal, etc. classic definition of depression.

He diagnosed me as having a depressed state of functioning. I had extreme flat affect. I struggled to communicate. I would struggle to finish a sentence/thought. I had a scattered presentation. It was like I was not there in my body. I looked gaunt. I lost weight. He explained it as a chemical overload of my brain cells due to stress and over-attending. It had been years since my last minor concussion. I was just under stress due to being ripped off for hundreds of thousands of dollars.

Were you seen by a NeuroPsychiatrist (rare) or NeuroPsychologist ? What kind of diagnostic testing was done ?

I hope the concussion clinic can help you.