I'm all over the place right now...

My stomach has been acting up a lot lately, giving me all kinds of trouble. Since I've gotten home from college, it's been nothing but nausea every day. I've had the urge to vomit (and I have already twice), had horrible diarrhea, stomach bloating, and a lump in my throat when it gets bad. This has been all during just one week of being back.

The only things I can think of right now that might be contributing to it is getting back on a few medications after being off of them for approx. two weeks, switching my diet from college food/pizza to real food at home, and maybe even readjusting to how much warmer it's getting outside. That last one is pretty minimal, though, even though I do get sick from heat very easily. I'm also lactose intolerant, but I don't usually have symptoms this bad when consuming dairy.

Does anyone have any recommendations for calming my stomach, or should I just let it pass? Ginger ale and Tums have become my two best friends over the past week and I wonder if there's anything else I can do.