I know how you're feeling. I don't know if it's from the meds or not, but that has happened to me after every treatment cycle. MH and I think it's partially just the fact that you're to a point where there's nothing else you can do. During the medication phase you're proactively doing something to prepare for the procedure. Afterwards, all you can do is wait. It's torture. But, I'm also sure it has a lot to do with the medications as well.
I hope you start to feel better soon!! ((hugs))