Hi Salsa, you poor thing, it sounds exhausting for you!
Just a thought...what is his bedtime routine? Does he get to the droopy-eye stage in the bedtime routine, or is he pretty much wide awake when you put him to bed at night?
I found that
DD was falling asleep during the last feed of the evening after her bath, and that lead to more night wakenings, because I was essentially feeding her to sleep. Now I feed her and then give her a bath, so she is wide awake at bedtime. She self settles really well, so she is then asleep without a peep at 7pm.
When he wakes after 40mins, could you send
DH in to do some rocking or patting or cuddling? I find if I go in
DD just wants a feed, but accepts a cuddle from dad more readily.
Also, I introduced a comforter toy, and that has been great to help
DD resettle. I put it in her hand as I do up her sleeping bag, and then she sucks on it to go to sleep. When she stirs, she then just sucks on it to resettle.
Hmmm...that's about all I can suggest. I hope you get some sleep soon. GL with it...