my DS was the same - right down to the collicky behaviour & not liking a sling. time cured it for us because, as you said, trying (gently) to stretch it out just seemed to upset him rather than help. tbh though, in the end the time did pass quite quickly (even though it felt like forever at the time!). DS continued to feed pretty much 2 hourly around the clock i reckon till he was 9 or 10 months old but as they get more efficient at feeding, it wasn't quite the time consuming process it is at the start & feeds were over quickly.