RE: All by myself...
These feelings you have are certainly normal.Our ability to see influences are comfort level and our fears of getting lost.As others have said there is nothing out there in the darkness that isn't there in the day light.There are things you can do to help yourself out.The use of a flash light,a strong beam one will bring you a lot of comfort because your being able to see so well.Putting bright eye's thumb tacks on your trail in to and out of your hunting area can help a lot,especially putting the tack or tacks on the tree you are hunting from.I don't know how many times I have scanned the sky with a flash light looking for my tree stand up in the tree's,very ofte when I was standing right next to the tree it was in.That's another thing relax,see the humor in your fears,it is kind of funny the things that you do when were afraid.
If you are walking significant distances you may want to become proficient with the use of a gps.I use them in big country all the time.They are awesome once you become comfortable withtheir use.
Lastly,you can do what I do when ever I fly,surrender your life to god!(only partially kidding!)Good luck and have fun!