I'm having a big problem with my Lucid Dreaming

I've known about Lucid Dreaming for a few years now and during that time have experienced a number of failed attempts to become a 'Lucid Dreamer', mostly due to school or being busy.

Now I've finally got the time to do it, but there's a massive roadblock.

If I attain even the most slightest moment of lucidity my brain seems to shut it down. It feels similar to waking up due to the excitement except that I never actually wake up I just seem to stop dreaming.

I've written out a Lucid Dreaming Practice Plan- which is my own personal jargon for 'an exact plan for what I'm going to do when I become lucid', so that I instantly go straight to this plan but it doesn't work and I'm still being blocked.

This is frustrating beyond comprehension, does anyone have any advice or experience in this area. I feel as though if this keeps up that I may have to stop Lucid Dreaming all together and save myself the disappointment.

Thanks