My daughter had colic until she was 5-6 months. This was a nightmare. I know how you feel. I used the following methods....I used white noise (I still use it to this day and she is 4 years). I would also use a vaccum. In fact, I burned up two vaccums and a Dirt Devil. I would hold her with her, face down, with her head and body on my arm (holding like a football) and swung her back and forth. When It was unbearable I would take her for rides in the car. This one was hard, but I would just walk the floors with her (for hours). I would also rock her in a rocking chair and get close to her ear and say, "shhhhh". I know that sounds funny, but it worked. I would also sit in a warm bath tub and put her on my chest. The closness and the warm water seemed to help her.
I don't know if this would work for your son or if your son takes a binkie, but sucking helps calm and sooth a colicky baby. My daughter would not take a binkie, so I never got to try this one.
Colic babies miss the noise and comfort of the womb. So, anything that reminds them of their days in the womb will help.
It's almost over. Hang in there.