Trees have a resilience all their own. They know how to survive better than you might think.
Don’t keep staring at that sapling. It won’t grow any faster just because you look at it more. Plant it, give it a good watering, then get on with whatever you need to do. It’ll put down roots and grow upward on its own. You only need to check on it now and then: water it when the soil is dry, straighten it if it leans, and leave the rest to time.
One day, when you’ve forgotten it was ever a sapling, it’ll be tall enough to shield you from the blazing sun.