My puppy seems to be having panic attacks?

My chihuahua is just a little over 6 months old. She has always been very close to me; she likes to sleep on my lap and follow me around. I started noticing a bit of separation anxiety at an early age and I tried to help her get over it by not making a huge deal when I left the house or came home. Keep in mind that other than the times I leave for work, she is never left home longer than 2 hours. When I leave her someone is always home with her, and my other dog is with her as well. So I thought she’d be okay.

The past few times I’ve left for work she’s had really weird behavior that almost seems like a panic attack. She starts sniffing around, licking the walls, licking herself furiously, fast heartbeat, walks in circles, etc. Then she starts crying and will usually put herself in her crate where she sleeps. And she will shake and cry in there until I get home. I’ve not witnessed this myself, I’m just going off of what others have told me. I am really worried about her, it’s heartbreaking. What can be done for anxiety in dogs?