These things take a lot of time to heal from, both physically and mentally. The damage and pain you suffered is the source of this, your brain has wired in to it now that speed and cars means pain. There are two ways to over come this and one to ignore it.
To ignore it, just give up riding your bike and stay nice and safe indoors. This sounds silly, but I have a friend who has done this and is now an alcoholic because they are afraid to go outside. I do not recommend this.
To over come it, you can fight through it on your own, or you can get a little bit of counseling. I have had counseling and it worked a treat for me. Working through anguish is hard work and difficult, but you can do it and you can get back on a bike again in time. Don't be overly harsh on yourself, but don't fall into a fear trap either.
You are not invincible, but you are strong and free and probably a bit creaky when you move now, but in time you will be OK, just don't give into fear. I speak as a former dangeorus sports freak who pushed the edge a few times too many, trust me, it makes us weird!
