Ugh !!! I wish you got responses back a lot sooner too.
You cut back pretty far and left no foliage, didn't change to soil, and the worst thing of all is that your keeping it in full sun all day! Don't do that man. Why sun if there is no leaves to absorb it? But there is still hope!! Ficus are strong trees and can survive a beating like this. You just got to give it the proper care. Keep it in the shade and keep a eye on it. Your tree is super stressed and bright hot sun won't help any. Shade it, leave it outside, and keep a eye on it. 10 days isn't very long to see results, some trees will but not it full sun like you said. It's like getting done surgery, you don't run out and play or work afterwards. You sit back relax and recover. That's what you need to do here. Also as weeks pass and see nothing still give the outer bark a little scratch. If green under the bark then there is still hope. If brown and dry you lost it my friend. Keep hope man! It's not the worst thing you could of done lol. Good luck