Stopping Pill - side effects?!

Help! I stopped my combined pill over 2 weeks ago now. The last 3 days I’ve had, at times, unbearable nausea, to the point it’s even waking me up at night! If I feel ok, I then eat a meal and instantly feel nauseous again, it’s like I’m right on the verge of being sick, but I’m not. I have also had a bad belly. Is this going to be a side effect of coming off the pill? If so, any idea how long it might last?! It’s making me feel awful. Thanks!