I slept sitting up with Miss I and Miss E for months but agree with the others that having him in any kind of carrier wouldn't be safe. I never dropped either of them but on the nights when I was just dead dead tired DH slept in the spare room so I could sleep in the middle of the bed so if I did drop them then it would be onto the mattress. I als put pillows or long cushions off the couch either side of me to support my elbows and arms a bit.

Good luck. Its an exhausting way to sleep on a regular basis.