Being nervous to get back on can go two ways:
1. You could be too nervous and unsafe in your riding habits. Fear could be an enemy.
2. Your experience in your accident could serve you well in that you will be incredibly alert and a very defensive rider.
I'm with the others. Go someplace quiet. Get a feel for the scooter again. Maybe start in a parking lot and work you way to quiet, low-speed roads. Stay on those until you feel like upping the anty and pushing yourself into more traffic.
Myself, I was in an accident almost three years ago. I'm' just barely at the point of getting back on. Am I nervous Sure as hell I am! My thought process is this: The odds of one accident were slim, the odds of two are slimmer. Doesn't mean it can't happen, but it does mean that I learned a whole lot about what to do when riding - hi viz gear, and watching my 6 more closely (was hit from behind).
Also keep in mind, there's no shame in not continuing on your scooter. If you get on every time and you're fearful, what joy are you going to get out of that? If that's the case, Stig's suggestions are perfectly suitable for your situation! Hell, I've even seen some creative off-road scooters recently haha
Be well, be confident, and let us know what you decide.