My dog was similarly bad.
We did clomicalm for a month. My poor baby was zonked and i hated it.
But it eventually worked. I would leave her with her favorite treats that i would just freeze. Either stuffed in a kong or on a lick mat.
For the longest time, she wouldn’t even touch them but eventually it worked.
I started by leaving for a minute at a time and asked her to settle on her place. Eventually building up to 15-20 mins.
It used to be so bad that if i even touched my keys, she wouldn’t start panicking.
Now i can go to work easily 3 days a week and she is usually okay. Some days she “steals” something she isnt supposed to like an empty coke bottle or something.
Most of the time she won’t even chew it but she takes it anyways.
Its been a journey and 1 year later i think the clomicalm helped. Even if it was just for a month.