14wo DS has never been a great sleeper but about a month ago had been going down about 10pm, doing almost a 4 hour stretch then maybe 2.5 hours then another 2 and then 1 til morning, which was fine. He then went through a week of waking hourly and since then has not slept longer than 2.5 hours at a time. He's a big baby (98th centile length and weight) and ebf. When he wakes he will not self settle - I always wait to se if the grunts subside but they always turn into full blown crying. The only thing that gets him to sleep again is a feed and he must be hungry because he eats for 20 mins.
Is this normal?! DH and I are getting increasingly frustrated and have no evenings together - I am inevitably in the dark trying to get DS down. We have a bedtime routine of bath lullabies feed starting about 8pm and have tried earlier and later but nothing seems to work. I can't see a point where he will ever sleep through the night, to be honest I'd settle for 4 hours at the moment, and it.'a really getting me down. He naps well in the day but to be honest whether he naps well or not has no impact on his nighttime sleeping.
Please help! I don't know what we're doing wrong!