when you are having a lucid dream, can you just wake yourself up?, and also, can you stop lucid dreaming and just drift into normal dreaming?
Yes to question 1 but Why would you want to change back to a ND or normal dream.
Yeah i woke up once it got really scary
ANd yes you could change into a ND my subconsious does it all the time … Stuborn subconsious
Yes, you can do both. To make up I get really excited and just go crazy, similar to what makes people wake up when they have their first LD. To slip into normal dream let your awareness of the fact that you are dreaming slip away.
well if something real bad is going on in your dream your body will naturally wake itself up, but yes, it is possible to wake yourself out of lucid dream. If I close my eyes for more than 5 seconds in a lucid dream i wake up. There are other ways to wake up such as just trying to feel your body lying down on your bed, its pretty easy really you just need to make a conscious effort to wake up.
How could you have a scary LD? By definition you KNOW it’s a dream!
just because you KNOW its a dream doesn’t make it good. you could be in a bad dream when you become aware, or you might not have full control and someone could shoot you and you might not be able to stop the bullet.
Yes but why be afraid of that bullet?
You can wake yourself up, but you should do a reality check after you force yourself to wake up, the amount of false awakenings i have… its ridiculous 
if you’re lucid in your dream try this; say to your subconcious that you have to wake up right now, i sometimes say, 'wake up or im gonna be late, ’ then i try and 'detach myself from the dream. hope this helps 
even if your not afraid of the bullet, it might still hit you and hurt whether you want it to or not
short explain: Some time ago i had a nightmare where random people under my house had a bloody fight. I was standing in my room, near someone that were looking trough window at it all. He loked like he was proud of it, he was just delighting by that all. It was light night, so i saw that he were holding something in hand. Knife, sickle, hammer, whatever.
Then i got lucid, but i was terrified, i were thinking “go away, dont look at me”. I was not afraid of being hurt - i knew that i’ll wake up. But i was afraid of all horrible, scary things he would do to me now.
So at one moment he realized that im here, he looked at me, and i decided to wake up.
Later i had a nightmare where i was him. Diffence was that those people were not fighting, but looking at me, waiting or something. Then i realized that im dreaming, and i had dream like that. I was too afraid to look back, not because of being hurt, but because of person i’d see. So i waked up. I wasted LD’s but it’s better that continuing it.
So as the topic thing, you can wake up, but do this olny if you must to.
Hmm, I’ve had bad dreams that I became lucid in, and the moment I did all my worries seem to instantly vanish. Maybe it is because I go to sleep with no fear, and live my life the same way. Making fear something you must overcome (for instance, waking up for a scary dream) automatically gives if power over you. But in reality you have control over everything in yoru life, nothing has any real power over you unless you give it to it. This applies no where better then in your own dreams.