Well, Welcome back to Healing Well. I'm sorry that you have had a setback in your depression.
You asked about your dosage of Effexor being upped from 75mg to 150mg. This is not a high dose at all. Many people take 300mg daily. I was kinda of surprised that you were stable on 75mg for "many years". I take 225 mg of Effexor XR (150mg cap & 75mg cap) and I feel great.
It seems that you have a lot of insight into your disease process which is good. I believe that some times you have to fall back a little to keep going forward.
A friend in need is a friend in deed. ~ mid 11th; 5th Century BC in Greek