Is it possible to still be experiencing daily migraines since my botox injection?

Almost 100% of migraines are Trigeminally Nerve innervated and correction of neural input can be life changing. A neuromuscular orthotic can correct improper jaw position and muscle function, the most common cause of headaches and migraines.
The Maxillary Division of the Trigeminal Nerve has the Sphenopalatine Ganglion attached and anaestheti applied by patients the the Pterygopalatine fossa can often give almost immediate relief of migraines, headaches and facial pain. Google SASPGB to learn more about Self-Administration of this Ganglion.
The popular book Miracles on Park Avenue told the story of Milton Reder an Otolaryngologist whose entire practice was using SPG Blocks.

Botox effects are temporary and typically wear off over three to four months, so continuing to experience issues this far from injection would not be likely. If you are not comfortable with your neurologist's assessment you may want to discuss it with another physician. Be sure to explain where the injections were placed and the dose used.

I have seen Botox cause headaches but since you already had migraines it might just be that it is not helping yours. You might want to discuss one of the monthly injectable drugs like Qulipta or Ajovy etc.
for your migraines with your neurologist as they are very successful and you can do yourself at home without need to go to neurologist for Botox.