I have slowly lost my taste and smell, what has caused this?

In the last year I have slowly lost my taste and smell. I can taste extreme tastes like sugar and salt. This started in Dec ,’16 after a bad cold and has gotten worse since then. My teeth have gotten really bad in the last few years and I am going in for dentures. I am 76. Maybe you could tell me what has caused this……(—)

Age: 76
Medications: Eliquis 5mg, cartia xt 120mg, terazosin 5mg and multi vitiamins.
General Information: No.