Q.cherry tree
Tree looks as if it’s dying. Leaves have not been a good green all summer, and have noticed holes in leaves. Keep watering but no different, flowers were white instead of pink. Could you tell me what trouble is, please?

Certified GKH Gardening Expert
This could be a nutrient deficiency. Leaves that don't fully turn green are often a sign of this. Here are some possibilities:
https://www.gardeningknowhow.com/plant-problems/environmental/plant-leaves-turn-yellow.htm
https://www.gardeningknowhow.com/plant-problems/environmental/leaf-chlorosis-and-iron.htm
https://www.gardeningknowhow.com/plant-problems/environmental/leaves-turning-reddish-purple.htm
Also check this article for possible symptoms of diseases:
https://www.gardeningknowhow.com/edible/fruits/cherry/cherry-tree-diseases.htm