Sounds like you had it bad. So maybe the ivermectin helped?
I did, and the doctors were stumped on how to help. My IBS was also affecting my vagus nerve which lead to arrhythmias and all sorts of other issues. At one time I had a gastroenterologist, cardiologist, and internist trying to figure it all out. The cardiologist wanted me to get a pacemaker, but I was able to control all the symptoms with diet as long as I was really strict.
Until ivermectin and I wonder if it was a parasite or inflammation of some sort. My arthritis got better for months after taking it too. So who knows. My GP says I should take ivermectin on a schedule, like 4 times a year.