Hello,
From the symptoms chances are there that it is due to tendonitis or some hematoms formation due to trauma. Had it been a fracture the finger would have swollen. However to completely rule out any fracture even as mild as hair line fracture, I suggest you to get an evaluation done by getting an x-ray Of the hand done. Till you get x-ray done, apply warm compresses and take some anti inflammatory pain killer after consulting your doctor. Also give complete rest to the part.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
You may have a ruptured tendon. Regardless you need to seek medical advice to investigate corrective procedures so you don't have a permanent disability. Fracture, dislocation or tendon - it really belongs in a splint to correct any deformity and provide rest.
its quite possible that you have either fractured or broken the finger this way, I have done many times! I visited A+E (or E.R) each time and had it splinted, just to ensure the swelling goes down as fast as possible. I'm confident now to do it myself, but to make sure its done correctly I would recommend a trip to the Dr! This will just ensure that the bone heals correctly, otherwise over time you could find problems in the mobility of the joint, or general pains.