I have neem oil so I sprayed my peach plant today. I also have copper but read once fruit to not use it. I think it's powder mildew. (Sphaerotheca pannosa)

But how do I now reverse it?

What variety is your peach? Most peaches are fairly resistant to powdery mildew. I agree that your tree and fruit look like it is infected by powdery mildew.

If you don't mind spraying chemical, try a Spectracide product called Immunox (contianing ingredient called Myclobutanil). You can find this product easily at Home Depot or Lowe's. Follow its label regarding how to mix it with water, how frequent you need to spray it. It should work.

please pick up all those diseased fruitlets and throw them out with trash. Do not let them lie around under the tree and do not put them in your compost pile.

Not sure kind of peach. Bought the house it was already planted and large. Nothing has fallen yet. So I used neem oil. Should I stop that and use the chemical you mentioned instead?? I rather not use a chemical. But if it's the only way. It's the only way. Can't tell the girlfriend. Cause she will be pissed if I used a chemical lol

Then, try wettable sulfur. Bonide has it. Follow the instruction on the label. You will need a sprayer. If it is one tree, maybe a one gal hand pump sprayer should be sufficient.

A peach tree should be prune to an open center shape. This will help sunlight penetrate inside a tree and improve air circulation, both would help reduce diseases.

There are many Youtube peach pruning demonstrations. Try the ones from Noth Carolina State University extension service.

Growing peaches organically, if you live in a humid area is very difficult.

I have grown peaches with limited success. I use the typical fruit tree spray available at the local farm & fleet store.

Are you sure you have a peach tree, and not an almond? They are close relatives. Here is a link to a photo of almonds on a tree. https://www.flickr.com/photos/sindy_nero/12015588/in/photolist-24zPj-okegsN-7KwVsm-4X36ik-4wwYJN-pmq8qA-5jHZQn-5jNeBf-4X36Xe-of1MBj-qT6Xos-5jJ9TX-ThPyDq-iqSnBJ-4WDDJr-TDUJbf-SMWmnm-TmrVoF-boL4LL-9Pjvdw-4XeHbC-SqYTHh-9PgEBF-LtKvu-4X352c-4WPaWM-9KB5Um-d5GVAy-8mgpEJ-QYkw2i-S7xVFx-re2gpz-4WqL6P-bqLUMh-9L84PA-9NNs8o-5jJ86i-9N7Nja-dz1B8W-aqS8M7-HaaFXg-rD7xDy-84cYpK-48CpBH-5jNh5o-RKzT2L-agqVFs-4kSUUx-5jJb4X-agcBq4

yea because they grow huge and turn peach color and smell good but fall off with that white mildew fungus patches on them..