Fruit trees need pruning right from the beginning. As your trees are 7 ft tall and flowering, I assume they aren't bareroot but, instead, came in a pot. Perhaps they were pruned the first year but, to have a healthy fruiting tree, they must be pruned properly every year. Maybe this will help.
They won't need fertilizer this year, but they do need water that soaks deeper than the bottom of the root systems. Roots follow water so the only way trees can grow a good sturdy root system is to provide adequate water. After the tree is established you can water less.
PS: It has been shown more than once that buying a larger tree does not mean you will have fruit sooner. Larger trees are more prone to shock so acclimate slower - the smaller trees always catch up in a year or two.