i fractured my skull in the back left part of my head and since the injury I have lost my smell and taste but I know what is good for us and still cook amazingly well
Anosmia and dysgeusia are common with URIs. Have you hade one recently (even as long as 3 months ago and I have heard of longer)? The other thought would be head trauma as Londres70 mentioned.
You can try sinus rinses. If this is persistent, seeing an ENT is advised.
Have you had any head injuries? How long has this been going on?