I don't blame you, its actually the most permaculture thing to do, rather then consistently battling against nature and the prevalence of those persistent distructive diseases. Lots of hardy options. They have disease resistant scions and matching qualities of diesease resistant rootstocks for apples concerning fireblight. Im not sure about peach cultivars, though, and the diesease in your area. The good news is, with all the types of fruit, you lave lots of options. Maybe try Pawpaws?
Probably not what you wanted to hear, but planting other trees not susceptible to the diseases in your area, will at least give you some hassle free options while you decide the fate of your other trees.
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