I need some advice from those who are experienced with this.

For those of you who know me, I'll refresh: My onset of full body polyneuropathy was in 2014 after about a year of dysautonomia, the painful neuropathy spread through my body with in 2 months. I was debilitated for 6 months with slow almost imperceptible improvement in which I regained some function, but life was difficult. 2016-17 had me at a stable but chronic condition which was manageable with the meds I have as needed to take when the pain and spasms are unbearable. Well... last month things started getting bad again. I started having symptoms reminiscent of my onset and have been having terrible excruciating pain.
My doctor decided for once and for all to try to be proactive about this and put me on 1000 mg infusion yesterday wanting to repeat this tomorrow and friday. His hopes is that it will knock this down and get me at least to my manageable chronic pain state.
So this is whats going on:
The infusion was at 4pm yesterday. I prepared by taking a zantac to protect my stomach as I can abolutely not tolerate oral prednisone so never got to take in for more that 3 days to see if it would have an effect on my condition.
I was slightly wired and had a headache after the infusion. By 11 pm, I took my pain pill to at least quiet that down. 3 am I woke up with bad nausea and severe sacrum pain. I ate something and then feel asleep from 6-6:30 am and had to get the kids to school with excruciating back pain and a headache. I was told that I might be racy, have stomach stuff, feel shaky... but that I should have an improvement in my pain levels even as soon as last night. What is up with the crazy back pain? Now I am really worried to take the next infusion.