If you're human, there's likely a chance that the hair on your neck stands up when the sun goes down in the woods. This is because for however many thousands of years, your bloodline has survived by not being stupid. Those who weren't afraid of the dark probably died somewhere along the way.
Congratulations, your survivor blood has made you freak out a bit at night! But you're not alone in this. Nearly everyone I've ever spoken to who's experienced in the backcountry has this same problem. I myself get a little creeped out when I'm hiking into a hunting spot early in the morning. It's even worse if I'm hiking out at night.
One of the biggest hurdles to getting into backpacking is being okay being out there in what seems like the middle of nowhere in the dark. I've met plenty of people who won't backpack because of this one single hurdle and it's totally understandable.
What I can tell you is this; it gets better and better the more you go. At first you'll feel creeped out, hear the tiniest of noises and think it's a bear, or not get a wink of sleep because of the fear of being murdered somehow. Stick with it long enough, and those fears will dwindle to the point where you're aware of what's around you, but not longer fear it.
So how do we get from point A to point B? Easy, work up to it. Go with friends at first. Build fires to keep you calm and sleep with friends in a tent so you're not alone. If you're worried about being eaten by a bear, bring bear spray or don't backpack in an area that has a high bear population. Take things bit by bit and prove to yourself that the dark isn't so bad.
Will you ever get over the fear of the dark? Maybe, but probably not. It's a built in fear that is there for a reason. Your senses have kept your bloodlines alive for a long time so learn to embrace it.
Just know this; everyone is afraid of the dark. If they tell you otherwise, then they're likely more afraid than you are. Don't let this fear hold you up from seeing the things you want to see out there in the wild. Bit by bit you'll learn to be comfortable and before you know it, you will no longer focus on the night.