I really feel for you, insomnia is very cruel. I have been suffering from the 'stress' type, i.e. I go to sleep quickly and deeply but the slightest thing wakes me after 4 hours and then I spend hours trying to get back to sleep because my mind has woken up and has gone immediately into busy mode.
I have tried all of the following and genuinely sometimes they work and sometimes they don't but anything is worth a try:
Lavender and/or Rosemary - drops of essential oil in a bath before bed and on your pillow
Drink of milk (unless you have a weak bladder) warm or cold doesn't matter, just makes your body feel full and content
Read a few pages of an enjoyable book, whatever rocks your boat, until your eyes become sleepy, this really helps to put your busy thoughts to the back of your mind. Also helpful to have a book for reading a chapter in the night if you wake up.
Have a dual control electric blanket so that you can put your half on whatever the time of night, my toes have to be warm before I can nod off to sleep.
Use the relaxation techniques that they taught you when you had your babies a) lie flat on your back and starting from your toes, imagine that that part of your body has gone to sleep and is heavy as lead, gradually move up your body, bit at a time and in theory by the time you get to the head, you will feel totally relaxed and more likely to nod off b) get into your most comfortable position possible and then imagine yourself to be in a beautiful warm place, i.e. on a sunkissed beach, the sun shining on you, listening to the gentle lap of waves, feeling the soft sand underneath your body, imagine feeling sleepy and drift off
Don't know if any of these help but just wanted you to know that I feel for you and it will pass but the situation you are in, waiting for everything to be completed is responsible for most of it and it ill get better