Head tremor more frequent /intense over last two years. Neuro not worried two yrs ago, do I need to go back to neurologist?

Yes. Yes yes also get super high quality mr imaging. 3t 32 channel head coil is what you should ask for and travel to if you need to drive to get one. It is worth asking for. It costs only 500 dollars at our facility.
Yes. Obviously it's bothering/worrying you. Go back to the doctor just to be sure. 2 years is a long time.
Yes. It's quite possible that your neurologist thinks your head tremor is due to essential tremor, which is a chronic, progressive but benign condition, largely hereditary. Head shaking is not uncommon in essential tremor. There are many ways to treat it, including primidone, beta blockers, gabapentin, benzodiazepines, and even botox. See your neurologist to discuss your diagnosis/treatment options.