Please, please help me shut down at night, I'm losing my mind

I'm a long term insomniac who can get to sleep fine at the start of the night, but after my first wake up I get stuck until the sun comes up.

I also have a 6 month old who is exclusively breastfed and currently cot refusing so we're co-sleeping.

I've tried everything over the years, medical and non-medical, including sleep clinics, and the only thing that's ever helped is sleeping pills or things like valium. I can't take those meds because of the breastfeeding and the one drowsy making med that's safe for me to have, has such horrific side effects for me that it's not viable. I got discharged early from the sleep clinic being told my issue is psychological not physiological. Idk if that's wholly the case, but I know that right now my issue is psychological.

Cuddling up to him and listening to him breathe often actually helps me calm down and relax into dosing off again, but the co-sleeping makes it hard as he'll move and disturb me drifting off. He wakes for feeds every 3-4 hours and often in between at the end of his sleep cycle and needs soothing back to sleep. Some nights that sees me dealing with 3 wake ups (gold dust) sometimes 8. It is physically impossible for me to go back to sleep that many times in a night, I'm lucky if I go back to sleep after 1 wake up.

A lot of my old tools aren't available to me owing to having a baby sleeping on top of me (turn a light on and read a book, get out of bed and move around, go to bed later or wake up earlier) so I need to resort to psychological ones which has always been a weak spot for me.

Please share any relaxation or visualisation techniques that have worked for you, in detail. Focussing on my breathing doesn't work for me and I have one visualisation that helps but is so overused now it's starting to not work. It's incredibly difficult to relax when you're expecting to be disturbed any second by a shuffle or a cry or a twitch or a full on slap to the face.

I've tried asking in parenting forums to no avail, so I'm praying, praying, praying someone here has a trick up their sleeve that works with my impossible brain. I'm on week 7 of MAXIMUM 3 broken hours of sleep and some of that has been baby having a bad night but it's so frustrating when he has the rare good one and I can't make the most of it

SOS, send help please.