Baby wakes all night!

My son is 8 months and since he was 4

Months he started his regression waking every 2hrs then 5 mo he got better and was sleeping long stretches but since 6Mo he’s been back at it waking up every 2 hrs! I feel like Iv tried everything and nothing helps! I usually have to stand and rock him for sometimes 30 mins to get him back to sleep then he usually wakes up when I place him back in the crib! So then I try a bottle and usually that will work and he will fall asleep. Iv tried Tylenol because of the teething and nothing, and gripe water and nothing! Half the time I co sleep with him but my 4 yr is also in the bed so I feel like I’m on guard in case she kicks him or something In her sleep. But he also will only sleep 2 hrs and wakes up screaming. My husband hasnt helped at all so it’s getting very difficult not getting any sleep! Any suggestions??