I actually think it might actually be colic now. He woke up this morning at 5.30am, wasn't hungry (he'd fed at 4am) but was really squirmy and looked in pain from the bubbles in his tummy, poor mite. In the end he fell asleep on my tummy for the rest of the night.
That said, we actually had a better day today. I don't know whether it was the cranial osteopathy helping or the Cuski comforter thing I started using today. First nap he didn't cry at all (I'm not sure he actually slept either - heard him making various noises and he was awake when I went back in an hour and a half later... he was pretty tired later too - but still a major achievement.
He was overtired by second nap as a result, but I did manage to get him to sleep in my arms for an hour and a half by walking him up and down the living room. Not really a long term solution, but encouraging because a few days ago it would have calmed him a bit but not sent him to sleep.
Next awake period he was actually happy for a bit, and I managed to get some chores done. Third nap he didn't sleep at all. But I think 2 out of 3 is real progress. I just hope it isn't a fluke!!
My mum and her boyfriend came to visit and took ds1 out which helped too. Although I had to put up with boyfriend's comments that I was "creating" his non-sleeping by walking ds2 up and down to get him to sleep - i.e. giving him the wrong sleep associations. I was obviously spoiling the baby and I should just let him cry for hours on end. GAH!
I'm a bit worried that this attitude is going to be common. Ds1 was a difficult sleeper, and a few of my friends weren't very understanding that he needed a fairly rigid routine for all our sanity. Ds2 being a worse sleeper I'm just holding my breath waiting for all the criticism to start pouring in...