I Am Taking Qsymia... (just Started Recently... I Am Currently

I am taking Qsymia... (just started recently... I am currently on the "starter strength")
I am also experiencing Cold/Flu symptoms...
I have already experienced the nasty side effects of taking an antihistamine (Benadryl) with Qsymia...
I was about to try Astelin (which I have from a previous issue, but it looks like that might be a bad idea too...
What can I do for this stuffy head and runny nose that wont make things seem worse?