I need help! I left my window open the other day with my tree next to it. For a few days there were only a couple droopy leaves so I isolated it in a warm room with plenty of sun for two days. Now a bunch of leaves are starting to fall off and it doesnt look like a happy little tree anymore!

I mist water twice a day over the moss and leaves and I just watered with the bonsai tree fertilizer today ( I do that twice a year or so) any suggestions on things I can do to ensure the longevity of my bonsai tree?