Sinus or dust allergy?

PLEASE DONT IGNORE THIS POST. I REALLY NEED HELP. I have been suffering from blocked nose since my childhood. In my childhood,I used to face this issue only in winters. Over the years the situation has become worse. My nose is so blocked all the time that I cannot breathe. I survive on otrivin and if I dont have otrivin it becomes unbearable. I carry it everywhere I go. I visited an ent specialist in my home town (up),he didnt do any tests he just wrote down a long list of medicines (too many and too expensive). I had them for a week but did not have much relief. Today I am at a friends place and have forgotten my otrivin and I feel suffocated. I want to ask what doctor should I visit for this issue or what test should I get done? I dont even know if its sinus or some allergy. I really wanted to get treated. Where should i begin? I live in delhi ncr. So if you could suggest me any doctors here,that would be great. Please please help me.