Insomnia?

I have been monitoring myself pretty closely for signs of depression.
sometimes I do have a depressed mood and low energy, but I feel like I am basically able to get done what needs to get done. This mood is also not persistent. My appetite and eating habits have been good, not too little, not too much. The only thing that worries me is sleep. For most of my life I have been hypersomnic if anything. I could sleep anywhere, plane, bus, train, you name it. On my last work cycle I noticed that I was not sleeping well during the day. I usually have to set an alarm to get myself back up in time to go to work, but last week I would wake up around 2 PM and not be able to get back to sleep. I thought I would catch up on my off-week, but I have converted very badly. I can't get to sleep until 4 or even 5 in the morning and then usually only sleep until noon or sometimes 2 in the afternoon. If I make it till 2 PM I am usually restless and dreaming for the last few hours. I have been rotating between days and nights for about a year now and it has never gone this badly. Normally after I get off from working I am sleeping 12 hours a night for the first few nights. I will be sitting around falling asleep at 7 in the evening. I am exercising and wearing myself out, so I am not sure what the problem is or even if it is a problem. I don't feel terribly dragged out when I am awake. Now that I am alone I feel like some of the rules are being re-written. It has also occured to me that not eating meat might be some sort of factor. My tendency to over-sleep seemed like such a fundamental part of me, could it possibly be lifting?