I noticed that happens to me a lot when I’m doing too much during the week and without realizing it really stressing myself out. I’ve noticed if I make sure not to work late and spend an hour or so doing something fun (like watch tv or draw) before I go to bed then I tend to not get that way as much long term. For the random days it happens I’ve noticed taking ondansetron has helped although my psychiatrist says it’s not usually what it’s used for (she gave it for the nausea from starting new meds) but I experimented and it does help me randomly when I need it to go away fast to function for the day. Maybe your doctor can find nausea meds that will work for you on those days too. That and self care basically treats it for me