You're lucky that your problem was not being able to wake up. The problem is usually the opposite.

People are considerably more likely to LD after undergoing intense changes in their lives (like traveling), so that is probably why you had one then. A lucid dream is simply a dream in which you know that you're dreaming, so if you did, you were having a lucid dream. People also sometimes experience partial awareness that they're dreaming, and it sounds like this might have been the case for you, since it was difficult for you to wake up and you felt fear even though you knew that you were dreaming on some level. If it happens again, try to make sure that you're completely aware that you're in a dream. Remember your daily life and that nothing you can do in the dream will hurt you. Then you can do whatever you want. Experiment, fly, talk to your subconscious. It's much funner than waking up right away.

I doubt that death will be like a never-ending dream.