Hi Fenella
Could he possibly have reflux? My lo was diagnosed at 4 weeks old and his problems were worse at his bedtime feed - sometimes he would spit up and sometimes not, but he aways seemed to have a lot of discomfort. Could be worth mentioning to your gp or hv to see what they think, as if he's windy or refluxy there's stuff that can be done - you might want to check out the colic and reflux thread. In my son's case, the gp said it was one of the worst cases he'd come across and he was given Carobel powder (a thickener) for his bottles plus paracetamol. We're in the UK and I give him Cow&Gate Comfort which is one of those formulas to help digestion.
One thing that I found did help my ds at night was to raise the head of his mattress a little, just using a folded up blanket underneath the mattress. I was also advised that after all his feeds to keep him at an upright angle (eg sitting in his bouncy chair) for half an hour after feeds to minimise the reflux.
Sending you big hugs too!