Where in the world are you located?

Sydney, Australia.

If you are going into winter, the leaves on the peach looks normal. It looks like you might have a sucker coming below the graft on the bottom. The leaves will sometimes fall off the tree in the fall based on reduced daylight hours. The leaves do look disease but they will look that way in the fall. What is your low night time temperatures?

It's still summer for another week. It's been really warm overnight, 20 degrees Celsius.

The goo on the tips is most often oriental fruit moth. Its a Chinese moth but has probably made it to Australia by now.

The peach looks like the main tree may have had some damage to the bark? Look at the base. The part that is really green is healthy, it is a different shoot so that indicates you have some problem with the other shoots but not the whole tree.