I'm sorry to hear about your accident. God is so good and he was watching over you all that day. Prayer helps me so much.
I don't know if you belong to a church or not. In our church, we have Stephen Ministers (Lay Staff) that can listen to you and be a friend to you. We are Methodist and maybe when you get back to Texas, you can get more done when you are home. It isn't really counseling, cause they are professional paid counselors. I've used a Stephen Minister and it is very comforting to have them when you go thru tough times.
You could talk to a friend or a Minister. You could go and get professional counseling. If you are having trouble sleeping, try taking Tylenol PM for a few nights and if that doesn't help, then go to the Dr. and see if he can give you an medicine to help you sleep.
You could try journaling. Sometimes I do that at night when I can't sleep, if something is bothering me, I will journal. Get a notebook or blank journal type book from a bookstore and use that to write your thoughts in. I write about my feelings and what is bothering me. It really helps me. You could read a book to help on anxiety/stress, that will help with anxiety.
I have anxiety and I am taking medicine for it. It really is helping me. You might want to consider medicine as an alternative to helping you. I would certainly try the counseling, the journaling first and then use medicine as a last resort type of thing.
I've had accidents before and it is very frightening. I had trouble sleeping the first couple of nights after the accident. Mainly, because I was in a lot of pain. I will pray for you S. and hope that this situation gets better. It is a miracle that you are alive! I've been in several accidents and have had mostly neck/arm injuries from them.
When I had my accidents, I hated driving after that. Over time it did get better. It will take time for everyone to feel comfortable driving again. Play Therapy helps with kids, if there issues continue. For right now, reassure the kids that that driving in a car/vehicle isn't bad. That was an unfortunate accident that you all went thru. I would pray with your kids and pray for safety, health. I would play some soothing music on the radio, calming music while you are driving. You all could sing too, some fun family songs. That might help the kids. You might look online for other suggestions on calming fun things to do in the car while traveling with kids. Hope this helps.