Perhaps you're ready to pop this one in the ground and move on
It let you experience a major chop on a pine and you learned how to keep a pine alive and healthy. You can always reconsider and pot it up again if the tree starts to show promise...
After you dig the hole for the tree to go in, throw a handful of triple phosphate (stimulates root growth) and a handful of slow-release fertilizer. These will give the tree a jump-start to overcome the change from a pot the the earth again
