Welcome to Mayo Connect @kim83. It's perfectly normal to be scared. I'm glad you are able to get in to see your primary care doctor today. He should have some guidance on what next steps to take. The nodule is in your neck, correct? Let him know that you are concerned about lung cancer, and he'll likely get you a chest x-ray or CT. That's a good next step.
Take a step back, and focus on what you know, rather than jumping ahead and focusing on what might happen. There's no need to feel ashamed or guilty, there's no room for that with everything else running through your head. What did your GP recommend? Are they able to get you in for an additional scan?