Our tree has a sappy hard dripping on the trunk, the peaches don't get big and are full of worms.
Certified GKH Gardening Expert
Unfortunately, this can be a difficult, and devastating problem to face. There are a few things that you can do, though.
This article will tell you what you need to know: https://www.gardeningknowhow.com/edible/fruits/peach/peach-tree-borer.htm