It could be CIH(cannabis induced hyperemesis). Basically, with some people who consume a lot of cannabis products on a regular basis, the body starts to experience a paradoxical effect. So, instead of reducing nausea, as seen by chemo patients who use weed, nausea is induced. It can lead to cyclical vomiting.
For relief, a very hot bath can bring relief. Also, taking a break from weed can “reset” the body.