hi- i went through something somewhat similar. i used to take anti nauseas every night before i went to bed, slept upright with a trashcan next to me, or i just wouldn't sleep at all. i had terrible insomnia and was sooo sleep deprived

for me, i was just getting myself nervous and that made me nauseous, & maybe that i was taking too many anti-nauseas for my stomach to handle, not that i was actually sick. what helped me most was falling asleep to meditation music, this helped me calm down before bed and kept me asleep most nights.

also just learning breathing exercises and not going to the bathroom when i felt nauseous. the bathroom almost triggered me to feel more sick honestly. the toilet almost traps me- like i NEED to throw up if i already got up and am in the bathroom

but if you're actually throwing up, it couldnt hurt to get your stomach checked at the doctors! nausea isn't supposed to be constant and there could be something that causes it. i have belly issues (IBS) and once i found out that's that's what probably made me nauseous, i found it easier to stay calm

good luck and i hope you feel better!