JedMarum is absolutely right. I went to an ENT & he told me my difficulty was caused by Acid Reflux. I took steroids for 4 days to reduce the inflammation & Nexium for a month. That solved most of the problem. I stopped having a tickle & irritated feeling.

However, I have noticed I'm losing my lower register. When I sing, I try to pick my sets with lower notes in the early set; leaving the higher songs for later.