Living In Humid Place, Get Profuse Sweating Leading To Nasal Block, Headache, Have DNS. Any Permanent Solution?

I used to live in Chennai,India and since Chennai is a very humid place and I had a sweaty body,whenever I went outside,I get sweaty and my nose invariably got blocked.Whenever I go or play outside or have a head-bath,essentially causing a lot of sweat/water on my head,I get my nose blocked and very often it is accompanied by a headache .During the winter season,this very often caused cold and fever.Once,it was diagonised as sinusitis .I also checked with an ENT specialist and was told that there was a slight septum deviation.They however told me that that was normal and relatively small and manageable compared to others.However,I have been living in Chennai from about 2 years of age but never faced a problem till I was 16.I later moved to Bangalore and did not face any problem in daily activities and the nasal blockage reduced a lot.I plan to get back to Chennai and I m seriously worried about this problem coming back.I recently went there for a weekend and again it caused me nose blockage after a head-bath. Its been more than 10 years and I have still not found a solution to this problem.I want to get to the root cause of this problem as it did not exist before in my life and get a permanent solution for this.Please advise me on the right course of action.