So ive finally had a lucid dream im not entirely sure if it was my first lucid but it seems like it because my other so called lucids didnt feel like this one. This one obviously started off with me running around aimlessly in my dream world accomplishing dumb tasks but THEN! I was in an empty classroom and for a random reason I thought “Hey I must be dreaming!” I got excited and did the nose RC and everything worked out I even looked at the classroom clock and it changed dramatically. I was then EXTREMELY pumped! I instantly got this amazing rush of energy that felt like xtc ^.^ and i remembered to calm myself down so I dont wake up but then still lucid All i could see is just blank white like a white sheet was thrown over my head it felt like this was all i could see for a minute and it scared me it also felt like if i opened my eyes in my dream i would wake up in real life kinda like i had 2 pairs of eyes >.> it was really weird. but I then thought of my house and a sunny day and I was there lucid for a little while longer except the methods to keep you lucid actually lost my lucidity xD. oooor maybe it was because i got distracted from my cousins dream character because i was talking to her for awhile boasting the fact that i was awake in a dream xD. but my question is why did my vision go blank like that and how can i combat that to make my lucids longer it felt like forever that i was like that.
That was probably just your dream fading away because of your excitement, nothing to worry about. 
With more LDs you will learn how to deal with this rush of enery so that you won’t wake up. First try out the usual dream stabilizing/prolonging methods, like spining, using all your senses and so on. What you did (visualizing a new dream scene) seems to work great for you, so why not stick with it if this happens again? Another trick i can think of is to command the dream to change into something else, maybe ask for colors, or imagine that the white vision is only a curtain you can easily tear open.
Thanks Leijona! well im almost positive it was my first lucid in over 2 years of non stop practicing on and off. maybe the white curtain is my subconscious letting me decide where i want to go? I used the Mild teq but this time i actually put a lot of thought into the meaning of the words i was repeating to myself and it actually worked 0.o so im gunna keep trying. It was almost instantly that after i thought of my house i was there. The thing is i tried the spinning and rubbing my hands together and it didnt really work it did for a little but not incredibly well I also feel like it was a waste of time. can you explain the fact that i was still semi lucid and looked at clocks but they didnt change they were actually going normally it was as if i was still lucid but was looking for proof that i was actually still dreaming xD