Long live my Apple tree

A couple of years ago, I was at Lowes and got me an Apricot, Cherry and Apple trees and with the help of my father in-law we planted them in the back yard. My father in-law noticed that the soil in the back yard is hardy with small rocks which makes it difficult for him to dig and he was also skeptical about 'if' my fruit trees are able to handle that condition. Well, we planted it and for about a year, they were growing fine, but I noticed that my Apricot and Cherry trees were bearing small fruits but it didn't go that far, and the fruits just disappear! After a couple of months or so, my Cherry tree did not make it at all, it died gracefully. My Apricot tree was left like a stump with no leaves on it! I thought my Apple tree would also have the same fate, but all along there were a few leaves and some bitty fruits on it, but this year, the leaves were all green and the fruits were bearing like crazy, to my amazement! The tree is not so tall, and with that so many fruits on it, it sort of droop to the ground, pulling the top or center to the side. I was thinking to myself, it must be the so much rain that we are having this summer compared to the last one.

Here is a picture of my apple tree.