You won't be able to keep it up. After about 3 days you're goimg to crash for several hours.
The body needs 2-3 hours of REM sleep just to survive.
It's a fun experiment though, I did it too when I was 17.
Interesting though that those with mood disorders (depression, specifically) actually spend more time in REM sleep than do those without mental illness. Even more interesting is that studies were done where they woke people up during different stages of sleep to record their dreams, and REM sleep was significantly correlated with more nightmares than earlier stages.