Hut in the Woods (2011)

Two misfit males, one man-child, one boy, find each other, building a small cabin in the woods to create a new life. Their daily struggle for survival creates a strong bond between them until the hut is destroyed and one of the boys carted off. The former psychiatric patient is told that his friend was just a figment of his imagination, but this provokes him to fight back and prove the boy's existence.

Unfortunately the movie Hut in the Woods is not yet available on HBO Max.