Ups and mostly downs with sleeping ..

My son is 6 months old tomorrow. For weeks he will sleep poorly (anywhere from waking every 1-2 hours all night) and then MAGICALLY for a few days sleep for 5-7 hours, wake to feed, then sleep the rest of the night. I feel tortured like I KNOW he can sleep “well” and I always get my hopes up that we got PASSED some growth spurt or whatever, but just feel lost and stressed that generally he doesn’t sleep well ever. I do the same sleep routines each night and it’s like Russian roulette .. will he wake up every hour or in 5? 😖 any one else go through this ?