If it's any consolation, you're not alone... I've had insomnia since I tested positive and I'm at 19 weeks now so you can imagine my exhaustion. Some days are better than others in the insomnia department, but it's just like you describe it and always around 2am. There are three things that have worked for me:
1. Don't take a nap during the day if you can help it (don't know if you're doing it). The more tired I am at night, the less I suffer from insomnia.
2. When you get up to the bathroom, don't think. Instead of letting your brain start to think random thoughts, choose a word and repeat it all the way to the bathroom and back. I choose "sleep", and I repeat it over and over again until I'm back in bed so that my brain doesn't start running off with what I have to do the next day or other random useless thoughts that will then keep me awake.
3. Use a meaningless mantra to lull you back to sleep. Once in bed, repeat a set of sounds that have no meaning to you, which is another way of discouraging your brain from picking up speed. I use "om nama shivaya", which is a meditation mantra, and it works really well.
Hope this helps... :) I see it as practice for when the baby's born. Gotta look on the bright side, right?
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