We wake up several times at night,  but fall back to sleep without even knowing. That's because we have conditioned ourselves to do that. Small babies are used to falling asleep by feeding, rocking etc and they get used to it. They don't know that they can self soothe and fall asleep without any of these props. We as parents have to help them realize that. Make sure u are well rested before trying this. One of the nights,  try letting him self soothe at least once.  Do not pick him up as soon as he cries.  Lengthen your picking up interval by few seconds or minutes each time. U may be surprised to see that one of these times he falls back asleep on his own. U can also take turns with your husband or a close relative which is willing to help