I Have Pain In My Right Hand, It Is Almost

I have pain in my right hand, it is almost in the center of my palm,
but above the center, concentrated in my middle finger knuckle
that's in my palm, not the knuckles on my finger. It is getting worse,
I can't straighten out my middle finger, and I'm losing control of the
finger. I don't recall injuring it in any way, but I gave it a month to go
away, just in case I did pull something, but it's getting worse. I know
my body well, I've played sports my entire life.