Go to https://energyswitchma.gov/#/ and sign up with a different supplier. Personally I'd suggest avoiding any that have a cancellation fee because if rates go back down, you want to be able to switch again. Absolutely nothing changes on your end, you still pay your bill as usual, you just pay less for it.

As a side note, it's unfortunate that you live in a National Grid electric town, they're more expensive than Eversource/NSTAR which is more common in Boston and surrounding communities.