NDW, have you had a general health check? Thyroids, blood sugar, iron levels etc?
I got panic attacks at night too, so that I would try and not to go to sleep. When I did sleep I would have terrible dreams, one typical one was that a killer was in the house, he'd already killed and he was coming for the kids. I couldn't get them out of the house, I knew he was coming but we had nowhere to go. I phoned the police but they couldn't find our house and I knew they wouldn't arrive in time. I woke from that in a panic, then I convinced myself I could hear someone downstairs, I convinced myself that the kids were dead in their beds and I stayed awake, panicking, until it came light and I got the courage to go and check on the sleeping children.
I also used to have vivid hallucinations of smoke billowing from under the door, that used to be quite common, I was sure the house was on fire.
If you are not sleeping and having panic attacks, if you are down, lacking in motivation, not eating etc then you are depressed. I have managed to hide my latest bout from dh until it got too much to bear. So if I can hide it from the man who knows me best, how much more can you hide it from work colleagues etc?
You need to confide in someone. Have you told your partner? Once you tell one person, you get the confidence to tell another. When you are depressed, problems become more so and you are unable to resolve them by yourself. You need another level-headed person to help you. Usually the answer is right there under your nose but because you are not thinking straight, you haven't grasped it.
I also thought that I was stupid, that nobody liked me, that I deserved to feel this way, that if I told anyone they would laugh and dismiss me as pathetic. I felt ashamed of myself for being so weak as to not being able to function properly. I thought I was a shit mother and a shit friend to someone who needed support, not some whinging cow who was crying because her ds had been sick on the bed. All of those feelings though are another symptom. You've got to shake yourself out of it.
After that night I spent awake I thought this cannot go on. I determined to pull myself together and tackle the problem head on. Hence the plan. I got angry with the depression for daring to come back, for daring to interfere with my life, for daring to affect my enjoyment of my children. And now I'm fighting back. Hope you can too.