Hi, I am hoping someone out there can give me some advice. I have a small olive tree that is a little under five feet tall. I have had it for only about seven months but it has done fine and has grown quite a bit in that time.

It is in a very bright spot in front of a bay window with three windows facing due south, SW and west. Last week I noticed a lot of leaves dropping and now suddenly I would say about 80% of the plant is dead and just has dried up leaves on it. The top where there are some live leaves, it looks a bit powdery.

Does anyone know what is going on and why so suddenly this has happened? And what I can do please?