Not sure how helpful this will be as we did the worst thing (according to all the experts) and were completely inconsistent.
We didn't do full-on controlled crying (I couldn't face it), but did try giving the baby the chance to settle himself, by leaving him for maybe five minutes, re-settling, and then no more than ten minutes. We would also go in if he was clearly sobbing hysterically, rather than wailing a bit. We used lots of rocking, shushing and rhythmical patting as well. Co-sleeping never worked, as he just seemed too hyper-alert and distracted by us, and I was also too scared (small bed, v. tall, heavy-sleeping husband).
We had some terrible nights, and I never thought he would learn to settle himself, but eventually (and it was probably just after four months, when he learnt to roll) he just did, and the sleeping has improved since then, with some wobbles.
Don't feel bad about wanting to try controlled crying though. Lack of sleep is more than just an inconvenience to parents, it can make you feel seriously unwell, mentally and physically. I think at this point, having 'a plan' is comforting because it makes it feel like you are in control, but muddling through probably works equally well. Make sure you are getting out and getting plenty of fresh air and sunshine though, it should help you both.
Also, what is the baby like during the day? If he seems uncomfortable (writhing around and archinghis back, wet, smelly belches etc) then could he possibly have silent reflux?