Did you transplant it when it was actively growing? If so, that'd be a mistake.

I would say it's not worthwhile messing around too much with that tree, but instead take advantage of it being a very good time of year to order a new tree to replace it. Since it was a young tree, you would not have lost too much time.

Also, when you plant a tree, do not put fertilizer in the hole/mix with natural soil. Use natural soil to plant your tree. If you want, put compost on top and mulch it. Watering regularly is most important, not fertilizing. Too much or too little watering could hurt a tree, too.

Never move a tree when it is actively growing. Wait until it goes dormant and move it in early spring before a tree leafs out.

Oh well, live and learn. Yes, it was actively growing. Let's see if it comes back in the spring.