That sounds very frustrating. I had low blood pressure when I was anemic and I had a very high heart rate.
Perhaps you should look for a different endo, the one you went to doesn't sound very effective.
Have you seen a rheumatologist? Maybe you have an underlying issue that causes the fatigue, like Fibromalsia? I always think I have that but my doctor says I don't. I hope you can get to the bottom of the problems you're having. It sounds like you are starting to see some improvement. 3.5 hours is pretty good, if only you could go 5 or 6 hours and get a decent nights sleep.
Sorry you're feeling bad.