Most of the time spent trying to have your first lucid dream comes from not knowing if you can do it and lacking the confidence that it takes. You already know that you can do it so that is no longer a problem. A lot of times people will have a lucid dream the first night they start focusing on it again.

I'm not sure why anyone would be afraid of having lucid nightmares; if you know it is a dream you should also know that nothing can hurt you and that you are in complete control. Some of my favorite dreams are experiences that might be scary if it was real like zombies, monsters, etc. Because I know there are no consequences and I'm never in any danger so I can have epic battles and feel like a hero.