Any good anti-colic tips?

my 8 week old has crying fits usually twice a day that last anywhere from 30 min to 2 hours. he screams his head off and gets himself so worked up that he starts getting sweaty and his cry starts getting raspy. i make sure hes not hungry, has a clean diaper, i burp him, try rocking him, talking to him, give him a pacifier, putting him in his swing, ect...he usually stops crying after a while because he tires himself out eventually and pes out. is there anything different i could try to help shorten these episodes of crying fits? i'm going to be returning to work and taking cles soon and im afraid nobody will want to babysit him because he screams on the top of his lungs and theres no consoling him. any advice would be greatly appreciated...