Oh, my do you think God intended you to be waiting 15 years to harvest mango fruits from your own tree? Btw, they probably won't taste as good as the one the seed came from, they rarely come true from seed. The seed is probably from a grafted tree, also.
I think He made us (especially gardeners) intelligent and resourceful and that's why we have grafted trees that we can buy from other clever gardeners at a good nursery that will give us delicious fruit in 3 years.
Not sure how they will do in your very dry climate, but give it lots of sun, great soil and feed it well. Then, when the fruit does finally make an appearance, be prepared to fight every critter on the face of the earth for them. Raccoons, mice, rats, squirrels, birds and neighbors . . .
