There is a disease of peach trees called "peach leaf curl." There is also "fireblight" which affects stone fruit trees and is first visible in its effects on leaves.
I recommend taking pictures of the tree, the affected branch(es), and the leaves, and also a few sample leaves in a zipped-shut plastic bag to a nearby independent garden-supply store/nursery for their diagnosis and advice.
Depending on the situation, peach leaf curl can be successfully treated by simple means, by drastic means, or only by removing the affected tree.
Maybe you can get some good professional advice this weekend?
Cynthia H.
USDA Zone 9, Sunset Zone 17