I'd advise you to hold off on the electric brush. Put your tooth
paste back in the cabinet and try baking soda for brushing. Just
dip the brush into the box, get a tiny bit on the brush. Rinse
twice.

Try this for three months, and see what your hygenist thinks.
Mine was impressed all to pieces. Her and the dentist both. They
frieked when they found out I'd gone off fluoride. I love the
results.

A Cochrane meta-analysis using very stringent inclusion criteria came
to the conclusion that oscillating rotating toothbrushes such as the
Oral-B Professional series are better than manual toothbrushes,
providing that brushing technique is not optimal. You can get the same
results if your technique is perfect with a manual toothbrush, but many
if not most people aren't that dextrous. So yeah, it would be a good
investment. Whether it makes brushing teeth more pleasant is pretty
subjective - some people prefer it, others don't. There shouldn't be
any more of a gagging reflex with an electric toothbrush compared to
manual - if anything, there's less, due to the smaller brushhead on the
oral-b.

The electric brushes you can buy in supermarkets
(replaceable-battery-powered) fared worse than manual, but again this
may have a lot to do with technique.

Take care to get used to it.  I resisted the idea for months and hated it to
start with.  Now, 5 years later, if I leave home for one or several
overnights, the first thing that I look forward to doing upon arrival back
home is to brush with the electric.  I just feel so much cleaner.