Hey, you are NOT a failure, okay!
Your milk is FINE. It is entirely possible for breastfed babies to be colicky. And he may not even be colicky.
When babies get to this age, they go through a few rough patches. It's like they realise they're not in the mummy anymore and they're a bit gutted.
I would be, too. I mean, things were good in there - they were always the right temp, they didn't have to suck on anything or cry to get nourishment, they were comfy, etc.
Try two droppers full of Infacol before each feed. Stop and wind him every 5-10 minutes.
If you're finding it hard to get wind out of him just by sitting him up, try placing him on your lap face down w/a rolled up towel under his shoulder for support and rubbing his back. Or, stand up, hold him facing outwards, and cork him over your arm. Rub his back. Sometimes this helps bring up the wind.
Hold him a bit after the feed and put on a little white noise. Make sure the room is free from other stimulation.
Get mobile, pace the floor, bouncing him gently in your arms. Go for a drive or a walk if you're in a safe neighbourhood (ah, that was one advantage of DD1's being born in summer, those long days).
This will pass. When you get down, just repeat that over and over again.