When you found yourself awake did you do an RC to make sure, it could possibly have been a FA.
EDIT: and welcome to the forum 
Sometimes when you go lucid, your mind still isnt aware enough to keep you in that state. next time try something like “when i turn around my awareness will be increased!” and then turn around, you will be amazed at how much more vivid things can become, and just how much more control you will gain.
I do this every LD i have, because if i dont, the same thing will happen to me.
My favorite line however is. “Increase lucidity now!” that pretty much doesnt leave any loopholes for your brain to get out of it, you would be surprised what it can come up with. :o
hope this helps 
I have lost that skill too.
But it was mostly caused by the stress of constant nightmares, so I realized I was dreaming and forcedly woke up. If only I knew what was possible in such situations…