My wife and I picked up a coffee tree about 6 weeks ago from a local plant shop. looked healthy and green when purchased but has slowly gone to a wilted look on 3 of the 4 main branches. The plant has indirect filtered light from a south facing window. We water roughly once a week when the soil feels dry at the top. Tried a humidifier and misting every other day as well. Ambient temp is 75 through-out the day with ~ 51% humidity inside. In an 8 in planter as sold by the plant shop. We think we may have over-watered but really not sure. I am confused that 1 of the 4 main branches looks mostly healthy while the other 3 seem like their dying. Found a few white bugs (aphids?) on plant as well. Any help would be greatly appreciated!