Hi wizzer -
I'm sorry to hear that you were involved in an accident. Any accident, whether it's your fault or someone else's can be fightening as well as life threatening. I hope you and all those involved are okay.
I have a slightly different take on the "do negative thoughts lead to negative consequences" question. It seems to me, that when I'm in a good mood, I tend to be more out-going and people notice the smile on my face and are more willing to strike up a conversation with me, as compared to when I'm depressed and I have a scowl on my face, which tells folks to "go away". I also think that our own thoughts can sometime lead us to either make decisions or not make decisions. I mean when I'm upbeat, I'm more willing to take calculated risks, whereas when I'm depressed I'm more likely to "talk myself out of doing anything" or start thinking that everything is my fault and nothing goes right. The sort of "all or nothing approach".
So, I guess what I'm trying to say is I do tend to think that our thoughts have the potential, at times, to lead to reactions that may not always be to our best advantage.
Hope things start to look better for you! :)