Wow that first sentence was the longest i've ever read, have you come up for air yet!!
Unfortunately accidents happen, i've had two in the last 8 months, one which the other party is currently denying so know how you feel.
However, no matter how bad you feel it is really important to get back on the road and not leave it too long before you do, you'll get your confidence right back!
Also, i'm sure you will never, ever change lanes again without making sure there is no incoming vehicle on the other lane, regardles of who's fault it was this time. Things like this are going to happen many times in yur driving life and will only really make you a better driver.