Have you watered it really copiously? Like several gallons on planting and then a few more gallons every few days? Planting an evergreen in full bloom you need to treat it pretty much like a vase of cut flowers until new roots establish. Lots and lots of water. If your soil drains properly it is hard to overwater in the first few weeks. Wind increases transpiration so that will not have helped.

Don't feed it. That will do nothing until it's established a new root system.

eta Make that litres. I discover from your other post that you are in Oz. A couple of 10 litre cans at a time.

im not familiar with this plant.. but the green leaves look fine.. and the only thing drooping as best i can tell is the flowers ... if so.. if is very common to abort flowers if planting wasnt perfect ... watering i mean ...

see link about watering ... INSERT FINGER and find out if and when it needs water ...

ken

https://sites.google.com/site/tnarboretum/Home/planting-a-tree-or-shrub

I think the leaves look less than optimal myself. They lack gloss and turgidity and are curling at the edges.