I bought this awesome tree a little over a year ago because of the strongly fragrant flowers it produces. It did well up until 1 - 2 months ago. At first I thought it was from the hot to cold, cold to hot weather we've been experiencing in San Diego. All the new green buds and branchs have either browned, almost blackened at the tips and have died. Still looks like it's trying to bud, but I'm afraid those new buds will soon end up the same. What should I do if it's root rot? Re-pot? Is there any hope?