It happened to someone I worked with on the A2 near Dover. She just walked straight out into the path of his truck and there was absolutely nothing he could do to avoid it. Afterwards he said he did feel guilty because he saw her standing there and thought it was a strange place for a pedestrian to be and afterwards he wondered if he could have done anything differently. But what can you do if somebody is determined to commit suicide?
There was an inquest, and suicide was the verdict. He was determined not to let the experience destroy him, and it didn’t.
Same for you chap, a horrible experience but you just have to crack on.