I was reading
this article this morning and thought that it might be contributing to your problem.
When a
tree is transplanted it does not necessarily have the capacity to carry all of it's foliage. When this occurs, the
tree will sacrifice it's upper branches and keep the lower portion alive. It sounds like what your
tree is doing. This does seem to be a rather severe case so I assumed salt, coastal CT.
I hate to give advice without standing next to the
tree but I would cut the
tree back some. The roots will then have less
tree to try to keep alive. I think your heavy watering was/is a good thing and I would suggest doing it during any dry spell, the
tree needs the water and it flushes out the salt.
How you cut it back matters. You want to cut off the top, as much as practical and with a single cut. Something between 25% and 33% of the
tree should do the trick.