Oh God yes. I think I'm having one right now.
Like you, I don't avoid cheese like the plague, but I'm cutting down because it's not healthy. I tend to use cheese more like a condiment, just a sprinkle here or there once a month or so. I do NOT eat meals that are based around cheese. Ugh.
So last night I was painfully hungry, and my mother-in-law offers me some "cheesy bread" from the pizza place that she has gotten. It's basically white bread with a 3/4 inch layer of melted mozzarella on top. Whatever, even a healthy eater can indulge, it's not gonna kill me, right? So I eat 4 or 5 pieces of cheesy bread.
Almost immediately after, it feels like there's a hard knot in the top of my stomach. I feel queasy and riding in the car is not fun. Later, my head starts to hurt. My throat gets really phlegmy and I have to clear it all the time. Blegh!
Now it's 12 hours later, and my stomach has stopped feeling weird but my sinuses are aching and my nose is runny. My throat's still slimy too. Yuck. And I realize that when I was omni, this was how I felt all the time. I just thought it was normal. I really don't think I'm meant to eat something that makes me feel like this.