Maybe C2 injury?

Hey guys, I have a problem with my ring finger which startet 1,5 years ago. Back than I was bouldering and after the session I felt a small pain in the finger(see picture). I taped it and kept on climbing but the pain didn't stop. So I went to the doctor, he gave me a cortisone injection because there was water between the bone (middle phalanx) an the tendon. After that I took a 4 weeks break and did some yoga. So I started very easy climbing again and avoided crimps and pinches. So far everything was great but 5 weeks ago the pain started again so I took instantly a break for 5 weeks. Yesterday I tried to start climbing again. I did some 10 min sessions on a vertical wall with juges. So far everything was great but this morning I felt the pain again even it wasn't that strong as befor but now I'm not sure what to do? Can it be an injury of the C2 pulley? I would be glad about any advice, also for therapy. Thanks alot! Description of the pain: When I massage the marked area softly I feel a slight sting. Especially near the joint it's stronger. I can bend my finger all the way but at the end, when I try to push it against my hand it doesn't feel completely ok.