DC3 is nearly 4 months old and for the past month has been up at least every 2 hours at night. He's EBF and before this started he was sleeping 11 hours straight. I'm back at work (full time) and can barely string a coherent sentence together. I've been feeding him nearly every time he wakes, if DH goes to him with a dummy he goes nuts. I've been trying a bit of hand stroking/shushing, white noise, etc.... Remind me what might work? I think I might banish DH to the spare room and just co-sleep with him for a bit. My other 2 weren't great sleepers either, I'd forgotten just how exhausting this bit can be!!!
I did exactly what you have just suggested. Co-slept for a while in the spare room with 10 month old DS, then DH took over at the weekend. Luckily he wasn't in that phase very long, however had a bit of a regression again around 8 months at which point we did exactly the same thing. Good luck OP!