(hugs) sorry to hear about
your parents. I know anxiety/stress can do alot of things to the body. Do you think it may be this? If so, maybe getting your feelings down in a diary may help.
I also have a fear of vomiting. We're not alone as there's actually a name for it ... emetophobia.
I've noticed that wheat causes me to blow up, do you notice a connection with food?
I suffer from random nausea and take ginger capsules for this. They are harmless and can be found in some grocery stores and any health food store.
Hope you feel better soon