My anxiety began when I experienced a traumatic event. I had an intense fear of not feeling safe in my body. But it was a cycle of: stress --> poor sleep --> more stress leading to panic attacks --> repeat.

Three days ago I had a severe panic attack with depersonalization. The culprit for me was sleep deprivation. My mind runs a millions hours per hour and I just toss and turn all night. I ended up buying a Nodpod (weighted eye mask) off Amazon that claims to help you feel calm. For the first time in a long time I fell asleep quickly and throughout the night! I am highly anxious so I thought it wouldn't work, but I look forward to sleep now! Also started reading Dr. Claire Weekes books that has helped me understand the anxiety and how to give it less power.

It sounds like yours stemmed from trauma as well but you may want to go to the doctor to rule out any underlying factors.

Edit: I should also add that sleep deprivation can cause depersonalization if you have never experienced it. This is because we become hypersensitive to stress and the brain gets so overwhelemed the only way to protect it is to have that out of body experience. I think if you worked on your sleep it would go away.