Desperately need help with an extremely anxious dog

We adopted a Corgi a little over a week ago, and she's a wonderful dog. Extremely gentle, doesn't bark, and has no issues with leashes/baths/being brushed/etc. However she is EXTREMELY nervous. She is essentially always panting/pacing, and jumping at every little thing. This has gotten better during the day for the most part through slow exposure, but at night it seems to be getting worse. There is no new stimuli at night - the trigger honestly seems to be when my husband and I both fall asleep, and then it's on and off panicking as well as whining (which she normally doesn't do) all night until morning. She has no trouble napping/relaxing in our room (her safe space) during the day. I would love to get her crate trained in hopes that it helps this behavior, but right now she's so adverse to it (I can barely get her to stick her head in with treats). She also barely eats her food, so feeding her in the open crate has been ineffective. I know it'll take several weeks to get her crate trained, so I'm hoping there's something I can do to ease her stress in the meantime. A Thundervest just came in today and didn't seem particularly helpful, but I'll try it a few more times. I brought her to the vet today for blood work + additional vaccines, and everything came back good, so there's seemingly no underlying health issues.

Important things to note:

-She is 4 years old

-She was rescued from a puppy mill about a month ago from across the country, so lots of recent trauma to unpack

-She is currently in heat, which is adding on to her stress / decreased appetite (I'm going to get her spayed as soon as it's safe, just really unfortunate timing)

-My husband and I both work from home, so someone is with her all day (she is usually glued to our side at any given moment)

-We take her for at least 2 walks a day (30+ minutes) - on the longer walks (about 1 hour) she'll sometimes be so tired by the end that we'll have to carry her home, so I know her energy is spent! We also have a largish fenced in backyard that we let her run around in between walks

I'm hoping that she just needs time, but we're on day 4 of 3 hours of sleep, and I'm starting to lose my mind. Please help my husband and I help her :( It's almost 3am so sorry if this was an incoherent ramble.

EDIT: I turned on a bedside light, and now she's out cold. Maybe coincidental, but I'll see if it continues to help.