Greetings!

This afternoon while taking a nap I had my second (remembered) Lucid Dream,
I tried concentrating on the hypnagogia in my mind for as long as possible, until I suddenly felt Sleep Paralysis taking over. I remained calm and convinced myself there's nothing to be scared of and it's all in the mind and I went with the vortex feeling but then nothing happened. I tried imagining being at a beach, imagined how the sand would feel, the smell of the ocean, etc ...but still, nothing happened.

So I tried looking at my hands to see if I was awake or not and I couldn't see my hands!? I couldn't even see my arms? I told myself to stay calm so I wouldn't get too excited then wake up and I tried to look at my surroundings but it was kinda vague, there wasn't much to see. I think there was a wall (you know how some dreams are, extremely surreal) and nothing else.

I then tried to see if I could feel my face with my hands, so I tried to rub my eyes, nose, mouth and could feel my hands there but couldn't see them.
I started becoming a bit fustrated cause it was all too weird and having a Lucid Dream about nothing was no fun at all. Suddenly I was back in my bedroom (in bed) and felt the Sleep Paralysis feeling again so I tried to move my body/throw myself out my window but couldn't move at all. I eventually gave up and entered a normal dream.

Can anyone explain what I did wrong and why I couldn't see my own arms/hands? And why couldn't I change my dream?

It's the second time now where i've had SP and unable to move once i'm in a LD or change my surroundings.