Ds 3 is 5 Weeks old, 6 Weeks on Thursday. To start with, he was a fairly good sleeper, waking once in 7-8 hours for a breastfeed, then straight back off. Once a week or so he would have a night where he did not go back to sleep after the 3/4am feed, but that's fine.
For the last few nights, however, he has got a lot worse, taking ages to settle. Once asleep, he tends to go 3-4 hours. Sunday night was the worst yet. He took 2.5 hours to go to sleep, slept for 2.5 hours then took another hour up resettle. I tried bfing, winding, dummy, rocking Moses basket, lining basket with my nightie so he could smell me, holding him til he fell asleep, having light on, having light off. I don't know what else to do! I understand he's probably going through a growth spurt atm, but this is killing me 
I don't think it's colic, as once fed & winded, he will lie in his moses basket happily enough 80% of the time, but as soon as he can't see me or I turn the light off, thinking he has settled, he starts crying again. If I try to put his dummy in so he can comfort suck, he will often take in air at the same time. Really, he has only ever sucked properly on the dummy 2 or 3 times, so I think I will give that up as a bad idea 
In the daytime he is usually pretty settled, likes to be on me or at least to see/hear me, but is not too upset if he can't, especially if he can watch DS1 & 2 playing
. He feeds well (ebf), rarely taking in air or clicking, seems to get what he needs in about 10 minutes for 1 breast, sometimes taking a few minutes on the second, too. Over the last couple of days he has gone from feeding 3-4 hourly in the day to 1-2 hourly (growth spurt?). He's putting on weight well, last time had put on 2lbs in 3 weeks & is following 50 centile line.
He usually has a big (3 hours ish) wakeful period in the afternoon/early evening, then falls asleep when big DSes go to bed, at around 7-8. He can sleep for up to 4 hours then. Ideally, we'd go to bed then, too, but DH doesn't get home from work until 7.30-8 on average, so we have to have dinner once DSes are settled, usually finishing at about 9.
I guess this is just a situation where I'll have to think 'this too shall pass', but I'm finding it really tough, especially as we have to be up for school runs & I can't sleep in the day as I have DS2 (2.11)
Last night was slightly better - ds slept 11-3, then 5-7.30, when I had to get him up to do school run. I think it helped that he had a better pattern in the day - 4.30pm-8pm asleep, 8pm-10pm awake & happy, cluster feeding. But he still had 2 hours where he was just wide awake. It also annoyed me that dh slept through practically the whole time, waking only to criticise what I was doing. Admittedly he can't help with feeding, but he could wind, rock etc.
Can anyone recommend anything I haven' tried please?