How to manage a flare up.

Not had a flare for a few months, so had forgotten how bad they are. The burping is off the scale again. As soon as I take my tablets, or eat a tiny amount of food , the burping, bloating & pain start. I cannot remember how to sort myself out. This flare came out of nowhere and is into its 4th day. Barely eating, as everything makes me feel sick. Any advice for me please?