(((DPS))) The sciatic pain I suffer is excruciating as well. I can't begin to note the number of desperate calls in the middle of the night to my pain/stress psychologist! We now know that part of the problem for me is the swelling that occurs when the bone goes out that far, and I have a anti-inflammatory medication to take, along with the icing and stretching. I also learned I cannot push, pull, nor lift anything hardly at all, or the muscles pull the bones out of place (not just the back too!)
Such horrible pain! Please don't be surprised if the MRI doesn't show anything serious. Please realize the doctors might not understand at all, at that point, and refer you to your therapist. I hope it shows something fixable, if it shows anything, but nothing serious that requires surgery.
I learned not to push, pull nor lift...yet just this past Sunday I leaned against my desk, tush against the lip of it, and pushed it backwards from me on the tile. It slid fairly easily and I only moved it less than 6"...yet it put my sacrum out. I iced and stretched and used hot baths to try to keep pain at bay ... thinking I had PT on Monday. Low and behold, they "forgot" to tell me the PT was out on Monday!! But yesterday he saw me as usual and got everything close to back in place. I'm still cautious about moving around, but not in pain still. (Thank God for small mercies!) It's disheartening to realize I just can't do anything like that, even though I'm feeling pretty okay.

It's tougher to "make excuses" to others and say, sorry I can't help, when they see someone who looks perfectly healthy.

You will get through this. Hopefully, you won't return to this kind of pain.