Good Evening Doctir....i Am 29yrs ...now A Days I Am

Good evening doctir....i am 29yrs ...now a days i am getting dry cough daily since 3 weeks....in day time its less..but at night times i cant sleep...its continuos dry cough...from these 3weeks i hav used brozine syrup and benedryl dry cough syrup and alex,strepsils and cofsils too...but my dry cough was not decreased...so can u pls kindly suggest me how to overcome from this drycough..
Thanks
soumya