Change in Behavior After a Nap

So my puppy, Anna, is about 5.5 months old. She’s been doing great with training since my last post about her biting.

The thing is: my boyfriend and I left her at home for a couple hours to get some shopping done this morning. Nothing was different from the other times we left her. She had a treat, she was in her crate, had her toys. Before we left, she was very playful and happy. When we came back though, she was cowering in her crate. Ears back, tail tucked, and shaking. She also peed which she hasn’t done in there since she was about 8 weeks old. She’s acting very cautious of me and my boyfriend. She still seems disoriented and it’s been about half an hour. I’ve been hand feeding her the treats she likes and she seems to not trust it??? She also seems a little shaky on her feet. I’m just worried. Any and all advice/experience/anecdotes is appreciated!