You should see a doctor
Call a doctor and let him know. I had that same problem and i still do my doctor never figured it out. I do take anti depressants for anxiety and depression which helped it a bit and also beta blockers. Those meds will work if its nothing neurological. Some people when they are younger have tremors in there fingers read about it it can be quite common. I would say if it only happens when you try to use them it could be a good sign of nothing to serious.