Separation from husband, new apartment and dealing with separation anxiety.

My husband and I separated recently, and my 11-year-old dog and I just moved into an apartment.

He has never had separation issues before (had him since a pup), but since the move I can’t leave for more than ~30 seconds without him howling. He’s otherwise totally normal… eating, playing, napping, acting like himself when I’m home.

It’s heartbreaking and also really stressful because I start a new in-office job soon. (8 hours M–F). I can come home on my lunch break to let him out, but I fear the howling will start again when I leave.

I’ve read through the wiki and tried desensitizing, music, long walks, frozen Kongs/high-value treats, calm exits, etc. It’s only been a week (I know that’s not long), but I’m wondering if anyone else has experienced this kind of sudden anxiety after a move… especially with an older dog who never struggled before.

We’ve moved multiple times in his life and he’s never had this hard of a transition, which is why I feel so lost right now.

If you’ve been through something similar, I’d really appreciate hearing what helped or how long it took to improve. I know I need to be patient but I’m honestly a little terrified about leaving Monday.