I discovered a feeding problem!

AHHHH!!! I discovered a feeding problem that I have been having with Landon, but I am on a mission to get that fixed. I dont know how long it has been going on, but Landon has not been getting enough to eat when I have been breastfeeding him. I have milk but he must not be sucking enough out, which leads him to trying to punch me in the chest and him freaking out. Sometimes if you take him away too soon he squeals like NOOOOOOOOOO...I'm not done! Poor little guy. I just wish I knew about this problem before and then he probably would have gotten more sleep, wouldn't have had to eat every 1 1/2 hours and probably wouldn't have had as many trips to the doctor. I think what I thought was a gas and colic problem was a lack of getting enough to eat problem. I do admit that some of the time I think he did have gas but now I am thinking that part of that time he was just trying to tell me he was still hungry. Now that I have pin pointed the problem I will be forced to pump more, which I am ok with. He is now eating about 4 or more ounces every feeding and stretching his feedings, on average, to every 3 hours. I guess I can't get too upset at myself because I am still learning but I just wish I would've known so I could have helped my son sooner.