Help!! I think I had a low blood sugar attack but I'm not sure?

I just posted a question (go see it, it said that I recently became a vegetarian and have been feeling grumpy and weak, weak especially yesterday and today while doing cardio) and went to refill my gl of water, but started feeling light headed and felt like I was about to faint. I was right by the fridge, refilling water, and grabbed an applesauce which I could hardly hold because my hands were shaking very hard, and a piece of cheese. I sat on the couch and the fireplace's fire and its twinkling lights bothered me and made me feel worse... I ate some beans, as a complex carbohydrate, some sausage (I guess this vegetarian thing isn't working out), and a coke as it is sugary... It scared me... what could this be? This happened around 2:30 PM on Dec 4. It's now 6:15 and I'm feeling extremely tired, and a little weak, but other than that I feel pretty normal. What is this? What do I need to do to prevent it? Please help!