Getting ready to go drop Kalani off and hope I don't start bawling in the vet's office

Both he and Hoku can not understand why they're not having breakfast this morning. Will feed Hoku after I drop him off so he's not tortured by the smell of the food being warmed up.
Any advice for when I pick him up this afternoon? I got him some onesies and one of those inflatable collars. Should I keep him separated from Hoku in a crate so she doesn't bother him? When can he eat?
I will be soooo glad when this is all behind me! Thank you all for your well wishes