Yikes, I'm sorry you're in pain. From what I've read it does sound possibly like die - off.
Would it make you feel any better to know that today was my first worm passing day, hmmmmm????? Ohhhh, nasty! They were transparent like noodles and there was also - lord help me- a few pinkish ones that looked like little shrimp.
When my heart started beating again - lol - I decided they were better out than in!
Oh, and I did have stomach cramps last night, so that is interesting.