

Please help my gem avocado!
Hello, I purchased this gem avocado a few months ago. I got it in pretty rough shape, but was able to nurse it back to health and drive lots of new growth on the two branches it did have. But, I made a mistake and cut a longer part of the upper trunk that extended beyond the top branch and cluster of leaves off. After I did this, the trunk started turning brown and the top cluster of leaves look like they are dying.
I repotted the plant when I got it. The pot is sitting in a bigger pot with room between the bottom, there is plenty of drainage.
The plant is positioned to get pretty good morning light and some good filtered shade in the afternoon.
I have a moisture meter that I use to check and water when the meter starts to read "moist" instead of "wet"
Can I save this plant? Please help!!