Hi Annie - first, WELCOME to YT
!
You could try melatonin (helps for anxiety in dogs), and/or benadryl (could make them sleepy and calmer). Of course, you can run both of those by your vet who I'm sure is very familiar with both.
Another option is the ThunderShirt - have you heard of it? There are lots of threads here about it and people have had great luck with it.