Cheratussin AC and cough

I've been taking Cheratussin AC for just a couple of nights; not long enough to know for sure. At night because that is when I have this tickling type cough that wakes me up. But does it have a rebound effect?

I ask because my nose had been relatively open during the day - especially opened up during a shower. Now, for some reason it stays stuffed up.

Just took first dose and hoping it works, I'm coughing like crazy and can't get anything out and can't sleep at night cause the cough keeps me up, I'm curios about this Tussionex, is it appropriate for me to ask my doctor about using it instead if this doesn't work?

I've taken it 2xs now & have sharp/severe pain in my stomach & also my bck???? I've had tussionex (sp?) b4 with bronchitis & that didn't do this crap! Even the grapey tasting syrup doesn't do it either. While I've found grape syrup not as great on cough but the thick fruity tasting tussionex is good (just a bit stronger when I took 1st time I was cocky about it thought it couldn't be that strong..umm wrong!! Kicked my butt! It did work though!
Has any1 else had such a pain stomach or back when u took this Cheratussin AC?? If so please post...thanks.