Cough since from march 2020. Get cured.

I have cough since mar 2020.i had montek lc tablet for 2 months and i was good once stop taking medicine I got cough again. Doctor told me itsp allergic cough. I took for few months montek lc tablet then reswas and apex syrup.Then razo 20 for 2 months and mondeslor tablet. Some kind of icheness I am getting. I hv consultated so many doctors. As long as I am taking medicine I am good once stopped getting same condition. Daily drinking hot water, steam inhaltion with karvol plus. I did ct scan neck and chest but it's normal came. And blood test also normal. After I started taking nexpro 20 tab for 10 days then 1 month I was good but again I started with the cough. This time i am loosing my weight. But no fever only clear mucus I am getting. I dnt know what to do. Please advise. If it's allergic how long I hv to suffer like this. Is there any way to get cured.