Try other trees such as apples and pears. 5b is pretty cold im in 9b so I'm not sure what all you want or can grow but I do a poly culture and plant in guilds that way if I have a bad year with one thing I still get something else. Also I had peach borers a few years back but after planting onion, garlic and mint around the tree I stopped getting them for the most part.. This year my peach tree is completely surrounded by potato mint but I don't think that will grow in 5b. There are a lot of plants that can be used.

Good luck. Don't get discouraged we all have failures. Try as many things as you can and find what sticks.

Are you in Canada? Check with Palatine or Hortico nursery in Ontario Canada. They both sell fruit trees. They might have good tips for peach borers.

Currant, raspberry, romance cherry series, apples all good choice for colder zone

Thank you all for a nice advice.

I'm so sorry you are not allowed to spray your fruit trees. I don't know if blueberries are hardy in your zone, but I grow some and don't spray them and they do really good for me.