I think sleep deprivation has fully set in

my baby is now 5 months old. He has colic and cries all the time. i havent had more than 5 hours of sleep a night since he was born. We had a really good night of sleep last night but I was woken up by the sound of a baby crying...but here's the kicker, my baby was sound asleep. I swear to god I could hear a baby crying. I think I'm going to go back to bed now that I'm literally loosing my mind. if anyone has sleep tips for a 5 month old who won't let you step away from, please share, I may need saved at this rate.