Q.My peach tree leaves have turned yellow and are dropping off
For the last 8 weeks the leaves on my peach tree have turned yellow and are dropping off. I tried nitrogen and bug killer but I am at a loss as what to do. What is the problem and how do I resolve it?

Unfortunately I can't tell you what the problem is from a description "yellow leaves." You need to examine the leaves for things like spotting, leaf deformities, size changes, green veins, etc. While leaves simply turning yellow is a sign of nitrogen deficiency, adding nitrogen to the soil might not show a change in the leaves in only 2 months. And it's never a good idea to use a treatment without a specific pest or pathogen as target. Here's an article on common peach tree diseases that might give you an overview of what to look for: https://www.gardeningknowhow.com/edible/fruits/peach/common-peach-diseases.htm
The best idea would be to take leaf,branch, and soil samples to the nearest extension service, where they can identify the problem and give you a solution. This link will help you locate one: https://www.gardeningknowhow.com/garden-how-to/info/what-is-extension-service.htm