I will share my experience with you and I hope it may help you - at least a little...
I was dx with RA and my fingers/hands have same problems in the morning for about one hours severely and than throughout the day i also feel like they hard to bend and painful, stiff and swollen.
I also have very stiff ankles and legs, if i get up in the middle of the night to go to the lady's room - I can hardly walk.
You have to discuss this with your Dr. Please, do yourself a favor, it may be serious.
I keep my hands in a hot water every morning for minutes, this helps me with brushing my teeth and washing my face, other wise it hard to do.
Best of luck to you