I've changed my mind. I took some Mucinex today and I felt better than I expected. True, it completely kills my appetite, but it's not like my body is really going to miss those calories.
The other thing I'm gonna have to come to terms with is that dairy causes sinus problems for me, not just milk but also cheese. In moderation these things are totally fine and I actually think that in many ways my body is otherwise very well equipped to handle dairy: it causes me zero digestive problems and I think really helps me feel full. I don't buy the vegan propoganda, I think dairy is a great food, it just causes me these snot issues so I do have to moderate (I don't think butter is an issue at all though).
Lastly, I have to stay more hydrated.
-drink water, and don't drink coffee on days I take sudafed