I read the OP as a perfectly legitimate question. I really have no idea why everybody piled on you so hard, and it's especially confusing that Kaz said you might have a "medical issue" or something. Oh noes!!1 Not a MEDICAL ISSUE!!!11
If your jaw is tired, I definitely wouldn't call THAT a signal to stop eating, though perhaps it would CORRELATE with such signals. Instead, it's your hunger level, how full you are, etc that should tell you whether to keep eating.
What it means for your jaw to be tired is simply that it's not adjusted to the level of chewing that you're doing. It's like any other muscle or whatever: if you do more than usual, it gets tired, it gets sore the next day, etc.
Most people don't chew nearly enough, and if they go through a whole meal chewing as much as they should, they would of course "feel the burn" in the muscles moving their jaw. So how to remedy this? Just chew more and your jaw will get stronger!
In fact, not chewing enough seems to be a common modern world problem. You could imagine that back in the day, the ancients probably really savored their food and tried to extract as much flavor as possible from each piece of food. This ensued that they chewed enough, plus it probably aligned their hunger signal with their fullness signal so both happened around the same time.
But nowadays since our food is so abundant, people rush through their food and don't really savor it (because there's almost always more where that came from!), making digestion poor and misaligning the hunger signal with the fullness one, such that you get the classic situation where your mouth is still hungry but your stomach is full. Weird shit, but completely resolvable by chewing thoroughly and chilling out a bit and simply savoring your food.
But that's sort of a tangent that doesn't necessarily apply to you. Getting back to you in particular: You said you ate 2 lbs of meat. That seems like a pretty large quantity. I'd be careful about going so extreme. Everything (good) in moderation is truly a useful rule; eating 2 lbs of meat seems pretty extreme. Also, as a rule I've found that craving extremely large quantities of specific foods indicates some sort of deficiency, which you can solve more efficiently by simply widening your variety.