Just the other day when I was making a left turn on green, I forgot to yield and almost got t-boned. One of the ladies in the car yelled at me and there was also a cop on the other side of the intersection who saw the whole thing. I felt like utter shit and that, compounded with all my other problems in life made me pull over in a parking lot to cry.
Like the anon on here said, don't dwell on it. Doing so will just cause you to be in a feedback loop that makes you feel even more like crap. Learn from your mistakes and pray for wisdom. Whenever those negative thoughts come back either pray or just do something to take your mind off it.
This was just a small event in your life, and luckily nobody got hurt. So don't let things like this weigh you down and pile up, life will go on.