Close but no cigar

I`m still pretty new to this so I need some advice!
I had my first LD on purpose last week by waking up halfway through a dream then going straight back to sleep and realizing it was a dream. No probs.
Last night I tried thinking "I AM DREAMING" over and over again and after about 10mins I think it started to work, I saw images on my eyelids, felt like I was gonna float away and started hearing a buzz type noise. Then I freaked myself for no reason and sat up :doh:
I`ll try again tonight, but does anyone have any suggestions to overcome freaking out?
Cheers!

I try to focus on the back of my eye lids aswell.I normally end up seeing like shadows floating around in front of me. No LD's yet':('