I had a serious cycling accident (5 days in hospital, surgery, 9 weeks off work) in 2005, and was back on the bike 3 months later. I was slow, careful, and shaky, but I figured the best thing I could do was to get back out there. Give yourself all the time you need and DON'T FEEL GUILTY! It was an accident, but you are probably still suffering a post-traumatic reaction, so don't do anything crazy like sell your bike. This is not the time for big decisions. Just take it day by day, and when you feel it is right to get back on, you'll know.