I am a Jane too,, and I too have the defective gene,, horses!!! I have 7, 3 are retired 1 can't be worked and the other 3 are ridden most days.
I can totally relate to the winter being the hardest time to fast, going out in cold dark mornings and the physical work involved.
Thank you for sharing your story, always nice to hear someone who has the same defective gene! There is no cure,, except a daily dose of an equine cuddle!,