Young tree help

[align=left]A few months ago I bought a new tree, it was about 3-4ft tall and did very well at first. Now, the leaves at the top have started falling off, and I can't see any new ones coming out. Not only that, but new leaves have started growing only a few centimeters from the ground, at the base of the trunk. Are these new leaves the reason for the growth at the top to have stopped? Should I prune them?

Thanks for any help.
This is in the southern hemisphere, and the tree is a Acnistus arborescens, if that helps.[/align]

 

The southern hemisphere is a very big place:lollol:

I guess its winter now?

A picture would be nice.

 

Yeah, I only mentioned it to make the season clear.
Still one month to winter, though. Southern Brazil, btw.

I might try to get a picture tomorrow, when it's light, but it's pretty much what I described.