Hi Cheryl,
Just noticed that you used soda pop to correct your low. Keep in mind that pop really isn't a good correction mechanism, and has no nutritional content. If you have a low, correct it with something fast acting (soda pop is supersaturated sucrose (table sugar), with phosphoric acid that doesn't help with your calcium absorption.
After I was dx'ed with Type 1, I never had a can of (sugar) pop again. After figuring that one unit of insulin was 25 cents, I figured out that I was paying more for the insulin than for the drink!
P.S. You had your breakfast in the car? Where do you drive so I can make sure to avoid you? *gulp*
P.P.S. I disagree with your endo. It takes 2-3 days, not weeks, to notice a change in Lantus.
P.P.P.S. I change my basal insulin (Levemir) and Lantus based on how much exercise and fat I've had in my diet by +/- 2 units. Yes, I adjust my basal insulin! I need less when I've been active, and more when I've consumed higher-fat meals. Once you get enough practice with it, you'll feel confident on making your own adjustments. After having T1 for two months, my endo trusted me to make my adjustments, with her feedback during our 3-month follow-ups.