I would doubt that most of your current problem is in your head, you saying that the left bicep is now stronger than the right. And biceps are used , in a lesser role, when doing any pressing motion, including dips. Even exercises like skull crushers, pushdowns, etc. You are not holding a heavy weight overhead just from triceps involvement alone. (as to the above: though I do believe that the mind/attitude are 50%, or more, part of lifting)
One though may be a slight nerve cramping or pressure with-in the left tricep/bicep. This can have a root cause from around the traps and neck area also. Would suggest, if not done already with the rehab you went through, deep sport or Rolfing massages. Any path of a nerve(s) can be limited in function (nerve muscle impulses) which can reduce their full potential for max strength. May also suggest spinal (including neck/traps) adjustments. Good Luck.