Severe nausea 3 months after hiatal hernia surgery with mesh

I had hiatal hernia surgery with mesh on Dec. 22, 2016. I had a rough couple weeks immediately after the surgery but began to get better. about a month after the surgery I began to suffer terrible nausea and ended up in the Emergency room. My doctor finally gave me sufficient anti-nausea meds including Zofran, Phenergen, Compazine, and Reglan. I hate taking so much medication but what I really hate is still suffering daily nausea three months after the surgery. My doctor has taken an x-ray, done a contrast CAT scan, and an abdominal ultrasound and can find no reason for my nausea. It has to be more than coincidence that this nausea occurred after my surgery. Does anyone have any hope to offer?