Hello,
I have a Mayer Lemon tree which is around 5 feet tall. I bought it around November last year and since then, the tree produced plenty of loverly smelling flowers that turned into small fruit. The problems started then. The fruit fell off first and then loads of leaves. I was confused as to why this was happening to a healthy tree, kept indoors over winter.

Then the infestation came. It started with what looked like cotton wool on the branches, with sap all over the leaves. Eventually, this turned into scale. I tried to get rid of the small insects, using organic spray, but this didn't seem to help. I read somewhere that alcohol kills them, so I sprayed them with some cheap aftershave. This did kill them all off, but the very last couple of leaves eventually fell off a few days ago.

The tree is now completely leafless and some of the branches have started to turn brown. The scale has gone, but the brown is spreading to most branches. I have tried to cut back some of the dead wood

The tree is in full sun indoors, but I am worried that the brown will spread to all of the branches and the tree will eventually die off.

Please someone help. The tree has turned from a healthy specimen to a bald twig in the space of 3 months. Can the tree be saved?