Q.Planted 3 Years Ago And Was Doing Great. This Year We Came Back From Canada And Found That A Lot Of The Fronds Were Dry, And Even
before fanning out. I watered 7 gallons every night during the summer.
I trimmed the dry fronds That only opened them up partially, and dryer

Certified GKH Gardening Expert
It sounds like the issue started with overwatering, and progressed from there. Overwatering can leave the plant open to infection, which can appear as drying leaves. Watering even more makes the environment perfect for the infection, and not so great for the plant.
I would treat with a fungicide until you see improvement. This article will help:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm