1) Don't worry about distance
The important thing is that you're out there, you're running. It isn't important how far you go, how fast you go, or how you look. You can work on those things later if you choose to, but the key is to getting out the door and running. If you can get your shoes on and get moving, you're a runner. The biggest step has been taken.
2) Be practical
You can overcome so many fears by making some simple steps to avoid those worst-case scenarios. Get a route you know well, and know is safe. Find a short cut just in case you struggle or feel pain. Make