How do I stop coughing!?! Dry itchy throat!?

I'm 8 months pregnant and limited at what i can take. I've already taken two benadryl, and one mucinex pill. I'm drinking water, and gargling warm salt water, and I can't sleep because I can't stop coughing! & I DON'T have any tea, or honey. So how in the hell can I get it to stop. I'm getting irritated and I can't sleep!