I'm in northern Florida, zone 8b. We can grow hardy citrus here.

Over the last week and a half, my small Hamlin Orange tree has lost nearly all of its leaves. Up until then it was very healthy-looking, with a load of green oranges, a load of blossoms, and some new green growth.

Now all the old leaves have gone, the newer ones are curling a little, and the blossoms are dying. I've had the tree outside in a pot for about a year. I was going to plant it in the ground once the blossoms were done. The branches are still green.

It would put it down to the crazy temp fluctuations we've had over the last month (from 85 degrees to 30 degrees in two days, for example) but my other citrus is fine.
The other citrus is: Duncan Grapefruit in the ground, Satsumas in the ground, Calamondin in a pot, and Sanguinella blood orange in a pot. Maybe they were just in the right location and/or the right variety of citrus that it didn't bother them so much?
I have not been watering it any differently than usual. I did give it a little citrus fertilizer a couple weeks ago but the other citrus got fertilized too with no ill effects

What do you all think? And do you think the tree will recover?
Thanks,
Ann in Alachua County FL