Why would my 5 month old cry all day? Someone please give some advice.?

I am going nuts or at least I feel like I will. This past week, my son has just been extremely fussy all day long. I have tried playing with him, burping after feedings, gas drops, tylenol, benedryl (as approved by his doc) teething toys, and everything else I can think of. Is there anyway he could be colicky still. I did some research and it says they can be up to 6 months. This past week it has just been whiny from the time he gets up to almost the time he goes to bed. Anyone got any suggestions?