In regards to our business some people say "if you don't use it you loose it" - I don't necessary agree with that.
I speak several languages but utilizing daily only 2 so others are sort of fading out untill I travel to another country.
Guess what? That skill that you thought was gone comes back in a day or two - you don't loose what you've learnt, it's just sits there and waits untill it's needed.
It's nice when you have a chance to master it, though...
Anyhow, I would explore different opportunities outside your current employeer - job market is though but again, you never know.
You have a quite of a skillset to just let go.

Good luck and don't give up.