Bring a list. Embarrassment makes everyone forget things, including you.

Narrow conclusion.

Written confirmation email after every phone call. Cheapest insurance there is.

Ask for the longer appointment slot. Ten minutes is not enough for a complex history and pretending otherwise wastes both your time.

An inconclusive account is useful if it stops the next person mistaking a story for a controlled comparison.

You are not imagining it and you are not being difficult. Document it and take the document in.

It gets smaller. Not easy, smaller. That distinction kept me going.