Quote from happi:

Nothing has really said that nausea is a sign of heartburn

Hi
You may not find it written anywhere, but I can assure you that heartburn or overacidity can indeed cause nausea.

A good otc tablet is Zantac.
In Au we can get 28 tabs of 150 mg and need to take 2 a day. They advise before bed.

best wishes

Also try varying your diet. One thing that never entered my mind as causing my heartburn/nausea was peppermint. I was about living on Breathsavers and gum. Who would have thought? I finally went to the doctor, and found I had an advanced case of GERD (before anyone had ever heard of GERD). I've been able to control it over the years with diet and zantac. I now know what foods/beverages to totally avoid.

Good luck. I know how miserable feeling barfy all of the time can be.