CookieCows, that sounds like just the situation I had with my apricot tree. Prune your peach tree with a chain saw and start feeding it like you feed a plat of banana (a cup of 10-10-10 per month or equivalent). Skip having a crop this year for great crops starting next year.
Take a look at this picture of my apricot tree, you can see where the chainsaw cuts were made 4 years ago. It was a huge tree -- I probably got a 1/2 cord of wood!
