You have my deepest empathy--I have been through two cranky babies. There has been some excellent advice given here, but I will add my own experience, which may or may not be instructive. My first daughter, as others here apparently, swallowed too much air when she was nursing. I took her off bottles for a while and tried to burp her more vigorously. It helped take the edge off some of the colicky crying, but turned her off bottles entirely.

My second child was diagnosed with reflux at about two months and put on medication. She went from being a very fussy baby to a very happy baby within four days. She went off the meds at about eight months, and still will throw up at the drop of a hat, but has been a happy baby. Both girls spent MANY, MANY hours in a sling/Baby Bjorn, and that seemed to quiet them when they were upset and not in pain.

If you have tried everything, and nothing seems to help the crying, consult your doctor--there may be a medical reason for the crying. Then again, perhaps there is not. Regardless, as with all things, this too shall pass.