You have a severe case of peach leaf curl. It's a fairly common disease but can wreak havoc if left unchecked. I'm not sure if your case is curable or how much work it will be to fix but read up on peach leaf curl treatment.

Pull off those diseased leaves and throw in the dumpster. There is no spray that will help now. But late this fall and early next spring spray for PLC. You can have fruit next yr if you do a good job spraying.

I'm not experienced with peach leaf curl, but I see some other clues in your photo. I read that peach leaf curl is encouraged by cool damp conditions, so it expresses in cool damp springs, and is less problem in hot dry summer. Well, I see a big tree close by. Perhaps your peach tree is too much in the shade of that tree (all day sun will help dry off the water after dew or rain) and too much protected from air movement that would dry the leaves. Not only the tree, but the nearby fence and little cedars might cast shade and reduce airflow. The other thing is the rhododendron shrub next to the tree. Rhododendrons like shade and I think they like high humidity. Is that further evidence that you've got the tree in poor environment for a fruit tree?