I really like your post. I relate to it! You have written exactly how I feel most of the time, in a more succinct manner. Thanks for that.
I'm writing this at 5.30 a.m. and have been awake since 2.30 so I get the insomnia bit.
Thanks for sharing the bit about the sound of someone breathing annoying the crap out of you. I get that! My husband makes all kinds of noises. I sometimes flee the house and go tot he garden just to be away from him.
Then the neighbour's dog barks, another neighbour's rooster crows all through the early morning and day, the traffic on the highway doesn't stop, but some how all of that except for the dog barking is okay.
Like Jay mentioned, have you been to see your GP about how you are feeling?
Writing here and expressing yourself may help you as well.
There is a thread here about SLEEP, you might find some of the information there helpful to your insomnia. You could research Sleep Hygiene as well. Weird title, but helpful information about insomnia.
Check out MINDFULNESS that might help you feel more grounded and connected.
Write down your thoughts before you go to bed so they are out of your head. That might help with your sleeping. Or tell yourself you will deal with those thoughts in the morning. Easier said than done, but it does help.
Cheers for now from Dools