Sleep problem ruining my LD attempts...

Hello,

Just the last week, I've been experiencing some new sleep problems. I can still fall asleep easily in the beginning of the night, but now I always wake up after only 1-2 hours, and I've set my alarm for 4 hours (when I'm in REM). These early wake-ups disturb me and sometimes it can take some time before I can go back to sleep when I wake up. These unexpected wake-ups only occur in the first hours of sleep.

As I said, it's only been like this for maybe 4-5 days. Can it be due stress during waking time? Because I've had some of that the last period of time. Also, I've started playing a sound file on my mobile phone that is quiet for 4h30m before a wake up sound starts, but how could a quiet sound file keep me awake? These are the only things that I can think of that have changed in the last few days. So any help at all would be happily accepted.

/Martin