Something you are eating and/or drinking is probably causing the gas, if this has been going on since birth and you are breastfeeding. Little ones can be extremely sensitive to what you eat and drink. Think about your obvious gas makers...pretty much all green veggies, plus cauliflower, potatoes...well, let's just say veggies in general. That doesn't mean you should quit eating veggies...but maybe stop them all for a week, add them back slowly, and see when the attacks begin again.
Additional, carbohydrates in general, some fruits, fatty foods, dairy, and artificial sweeteners and sugar alcohols such as mannitol and sorbitol can cause gas/bloating/etc. Carbonated drinks are one of the worst.
It might be best to keep a food diary...do it for a few weeks...write down everything you eat and drink, what time you ate and drank it, and what time his attacks come on. This may allow you to narrow down what it is that's causing him problems. Or, if you already know you drink three cans of pop a day, for example, and he has three attacks...look for things like that.
My brother-in-law swears by some gas-drops for infants...I never tried them with my youngest, who is gassy to an extent, but he says they work wonders. I can't remember the name, but it's something you can buy OTC.
Hope it "passes" soon! :) All jokes aside, I do...I know how uncomfortable it can make a baby.