Trouble Sleeping

It's only 5:45am, I'm already out of bed and showered/shaved, and I don't even work today(unless someone calls). Last night and Sunday night, I went to bed relatively early, but mostly just laid there both nights, unable to doze off. I MIGHT have slept about an hour and a half total last night, but I've been awake since at least 3:30am. Figured about half an hour ago that I apparently wasn't going to get back to sleep, so just went ahead and got up. My eyes feel heavy, but I just can't seem to sleep...