I'm not pregnant but have been diagnosed with anxiety and depression that all started with monthly, pre menstrual insomnia. My doctors have failed to conclude that it was hormone related but the more I hear the more convinced I am of the correlation. I'm very sorry to hear you are suffering but by my knowing that this is something that occurs quite frequently during pregnancy is helping me feel more positive about my condition.
I did find that Badgerbalm for sleep helped me relax during the night and camomile tea too, but the thing I swear by the most is Bach rescue remedy, it's natural and says nothing on the pack about using it while pregnant but please don't take my word for that. I'm sorry I'm not more help to you than that but I'm sure that this is something that will dissipate when your hormones sort themselves out, I'm in the process of finding a pill to control mine and am feeling much better. Hang in there. I know it's tough being up for hours but the more you fret over it the worse the anxiety will be. Try not to lie in bed awake for more than a half hour, get up and do a boring chore (like filing bills or gentle dusting) for 20 mins then go back to bed and try to fall asleep again for only a half hour etc. apparently one of the most important things is not to train your brain into associating bed with stress and wakefulness. Good luck with your pregnancy and forthcoming bundle of joy, I'm sure this will all be worth it then. Remember, your hormones are just doing their thing for the baby, it just sucks that you have to suffer for it. Sorry to ramble on. Good Luck to you.