M.S.
Zinc Lozenges work great! I got mine at Sprouts but I'm sure you can find them just about anywhere. You allow them to disolve slowly in your mouth. I had a cough like you and a friend recommended these to me. I honestly couldn't believe how quickly they worked. Also, drink lots of fluids and hot water with honey and lemon!
Honestly in my opinion, cough syrup or any otc suppressants just mask the symptoms. You don't want to supress the cough, however I know that is tough when you are trying to sleep!
Hope you are feeling better soon!
M.