My was implanted are T6 to help with upper abdomen pain. Luckily I haven't had any nausea. I think you should set up an appt. with the doctor and rep.
My rep has been able to adjust the settings to move stimulation up and down my abdomen to cover the right area. I hope they can make adjust went to the settings to help you.
Are you trying to keep the setting very low? Maybe it's too much stimulation for you.

Sandy