If you’re making it on your own, the problem might be that you don’t press it. Unpressed tofu makes me feel sick too, and it’s really vital to do so so it can absorb flavors.

If it’s when you’re eating out, I’m not really sure in that case. Tofu can be anything from extremely soft to pretty firm, so it could be the firmness of the tofu that’s an issue here, but it’s hard to say. I like it when tofu is very firm and then cooked to be crispy personally.