Well first of all, I don't recomend using any sort of fungicide, pesticide or herbicide because for one: they generally cause more problems than they solve.
A better alternative would be to use a weekly spraying of neem oil.
As far as the browning of your tree, I am guessing that you probably over applied the fungicide and harmed the tree in some way. (Probably burned the roots) So, I would say, soak the tree ( pot but not the stem) in a sink full of water for half an hour to an hour. Then, leave it be for a while except for a daily misting.
Check the soil to see if the tree needs to be watered again and water if needed. It's a waiting game now.
Good luck with your tree.