I know I'm very late to this, but I thought I'd add a couple more ideas, in case you still need help.

• ginger. seriously, it's so effective (for me, at least), and relatively cheap. you can even buy it in capsules.

• peppermint oil. I get the worst motion sickness while riding the bus near me. I put just 1-3 drops inside my mask and it helps a lot. you might be able to just take a whiff of the bottle and get some relief, tbh

• it doesnt really sound like this is the case, but do you drink coffee or tea on an empty stomach? I used to be able to, but now the tannins always make me sick. :(

• I would suggest keeping a record of when it happens/for how long, what you ate/drank that day, what hygeine/skincare/cleaning products you're using, how much sleep you got the night before, if it's worse/better certain parts of your cycle, ect. it might help narrow things down.

I really hope your gyno takes you seriously. it sounds like you may need better doctors.

i suspect its hormonal but who could possibly say.

A doctor might.

Try those drug-store seasickness wrist bands. There's an acupressure point on your wrist that can be effective for nausea.

IME, acupressure works best when it's uncomfortable; I suspect it works by trading a lot of one sort of pain for a little bit of another, but that's just my theory. I mention this because if you try it and it doesn't work, find the place where applying pressure to the little plastic nub is almost painful.

Placebo or not, these are effective nausea control for my wife.

Also: ask your doctor for anti-nausea meds. They're not expensive, and while prescription, aren't class-3 or whatever it is that makes doctors afraid to prescribe them. They don't work for me, but they're 100% effective for my wife.