I had GI surgery, and afterwards, I had an "Ileus" (intestines don't move food through), which is apparently a low probability side effect. I was utterly miserable for a week, with horrible nausea and vomiting. Even water. If my wife had not made me go back to the hospital, I'd probably have died from dehydration.
I cannot imagine living with nausea for months or years.
Depending on the risk factors (prolonged surgery, open surgery, opioid use, hypokalemia, NG tube placement) postoperative ileus is seen in 10-20% of people after GI surgery.
Not to minimize the terrible subjective experience you've had. I wanted to point out that it isn't that uncommon.
I cannot imagine living with nausea for months or years.