You seem to either have too much water or burn from fertilizer. You might do a perk test near by to see if soil is not free draining peaches don’t like wet feet. If it’s water logged you may need to improve drainage. If you dig down near roots and find mud, that may confirm what I see
Good luck
Dennis
Kent Wa
The other thing easy to help diagnose remaining life would be a scratch test just above the graft union. If you see green cambium it may spring back again next year, as long as it is not over watered.
I agree with Dennis about the possibility of overwatering. We drowned a plum here one year. Turns out that overwatering causes leaf wilt that looks the same as that from underwatering.