I was on the edge of creating Separation Anxiety with my pup. The best thing that worked was putting her in the crate and locking it while we were home. We’d leave her in there until she stopped whining, and freaking out. Normally 15 minutes building to an hour. We’d just be going about our normal routine but wouldn’t be out of eye sight and ear shot. Then after that we’d leave the house for 10 minutes to 30 minutes, and kept building from there.
She was freaking out about being in the crate because it meant when she went in it, we were gone. You have to try and break that association, of crate=alone. After awhile she didn’t mind being in it, and when she would get tired, she’d go lay down in it. FYI – She’s still not a fan of the crate but doesn’t whine anymore.
She also didn’t like being in there at night. I made the mistake of letting her sleep with us for the first week, and then decided she needed to at least learn to be in the crate at night.
I would take an old shirt I had worn and put it in the crate with her, that helped a little. When things were looking pretty bleak and she was whining for hours, I took her crate and slept in our guest bedroom, so my girlfriend could sleep. It happened to be right by the AC unit, and the humming of that did the trick. Her anxiety lessened over 3-4 nights and I brought her back into our room where she finally slept without whining. Some sort of repetitive droning noise, like a fan or a clock that ticks has been known to work. After a 2-3 weeks of that, she could come back and sleep in bed with us.
It was testing at times, especially when she was whining so violently, you swore she was dying! I feel your pain!