How to get rid of this cough?

Ok. I've had this cough for almost 2 weeks. I went to the doctor tuesday. she gave me something close to claritol, benedryl,robitussum, and some antibiotics. All i had was the cough, but the robitussum isn't working ( i've taking a whole bottle's worth and my cough isn't getting any better). It seems like neither of the other medicines are working either. it especially gets worse when i go to sleep. i'm not coughing up that much phlegm either. I've also tried delsym ( i think thats right) I called the doctor and she said she would prescribe me something, but her nurse never called me to get the prescription. I need something b/c i'm going crazy with this cough. any good otc medicines for this cough? Thanks for any help.