First off the higher morning number is indeed the "dawn phenomenon" so don't worry about that, it happens to most of us. HOWEVER, your Byetta needs some help as your 2 hour numbers should be below 100. Your endo is right on the money to prescribe you extra meds. Amaryl is a med that will "increase your sensitivity" to insulin and one of the major factors of Byetta is to increase your insulin production in response to your blood sugar load. So the Amaryl will just give the Byetta a little extra help in getting your numbers down and keeping them down.
Now, skipping your evening dose of Byetta is NOT a good thing. Even if you don't eat anything, as long as your blood sugar is over 100, you should be taking your evening meds. If the Byetta and Amaryl push you to 60's or 70's then the dawn phenom. will pull you back up to just under 100 and you are right where you want to be. And remeber, the Byetta makes your body react to the sugar levels in your blood stream, so if you don't eat and your blood sugar isn't that high, the Byetta will have a negligible effect. Hopefully the extra meds are just what you need to keep your numbers mostly under 100. Good luck.