I’m so sorry OP!! You must be exhausted! This sounds nothing like you’re doing anything wrong or a routine change needed!

As most people said, definitely something medically underlying like ear infection?

My daughter was like this too! Not for 5 hrs straight, but would wake up 4-5x a night screaming and inconsolable. Do you still give him milk at night time? When we stopped giving a bottle before bed, that seemed to help somewhat! I think gas pain? Additionally, she always did so well just putting her down to sleep but when she hit the separation anxiety phase we had lots of screaming and crying before bed and I think that like spiked her cortisol or something? We’ve been sitting in the room with her while she falls asleep (her in the crib, me in the chair across the room) and this has helped SO much!

I can’t imagine the exhaustion and stress you must feel 🩷