I have a guava tree, not sure of the variety, but I had it grow in my garden, probably came in with some other veggies or something.

I left in in my garden until it was about 6 ft tall and had it replanted in a more suitable location.

It's been 10 days and it has dropped every last leaf the few remaining are totally brown, hard, and dead.

I scrape off with my nails on the outer branches a bit of bark and it is still green right under so it is still alive.

Please help me what to do in this case? I really do not want to lose this tree. I do not know if I should be watering, letting the sprinklers take care of it or what?

In the garden it was not being watered at all as my garden bed has been barren for the last year so it was not being watered other than the sprinklers, but somehow it is dying :(

Zone 10 here so it's perfect for growing guava, but please any advice to keep it alive as it is on its last leg.