Get your doctor to give you a referral to see an occupational therapist. It can help to split your finger to rest it to not let it get worse. They can treat you with massage and ultrasound both of which are quite nice and work. And you can give yourself hot cold water valves for your hands. Hot water is 110 to 120 degrees, Coldwater is 50 to 60 degrees. You start hot for 10 minutes, then you go cold for 2 minutes then you go hot for 2 minutes then you hot for 2 minutes. I also ice my hand before I play guitar. Heat will make your hands feel better but heat causes things to expand. Cold cause things to shrink and that's what you need to have happened you got a swelling in your hand you need to shrink it. Don't jump to steroid injections or surgery before you try occupational therapy. If you're over 65 and on Medicare you probably won't have to pay anything to see an occupational therapist. I don't pay a cent.