You may be in the early stages of insulin resistance. When you eat a carby meal your bgs spike very high. Your pancreas will then respond by making way too much insulin which hits you all at once . The speed of the crash may make you feel sick. Getting a bg meter at Walmart sounds like a good idea. Test 1 and 2 hours after meals and check out how high you are spiking. Many times fasting bgs are the last to spike in diabetics but you could still have a problem.