I dont know if anyone has posted this yet, but Cannabioid Hyperemesis Syndrome is a documented phenomenon. This can happen seemingly randomly to certain individuals who use any cannabinoid including the synthetic ones. People with this condition develop a sudden intolerance to cannabis, even if theyve been using it for years without incident. You will become very nauseas and could vomit. Many people who have this dont know it, so they try to treat their nausea with more cannabis which worsens the problem. A simple way to check if you have Cannabinoid Hyperemesis syndrome is by taking a hot shower while nauseas. For whatever reason heat will help tremendously, so some people will sit in their shower till the heater shuts down. If this is the problem just stop smoking and youll go back to normal. Tough advice to follow, but similarly to an allergy you should not continue to expose yourself to the substance you are reacting with.