Hi Loopy,
i really sympathise with you , as I have not only witnessed an horric accident but have also been involved in one, luckily I'm still a live, but it did take a long time to get over it. If you don't want to try drugs or the doctor's try taking St John's Wort every day, which is sometimes used for anti depression, but it is also used for calming, it works I've given it to my husband who is normally a buzzing person, also drink a few cups of camomile tea during the day and one about an hour or so before bed, it relaxes you and makes you feel naturally sleepy, as for the dreams they will go, and believe it or not the sooner you get some proper sleep the quicker they will go, as for now you're not allowing yourself to discharge teh days events in REM. Trust yourself, it's hard, but it wasn't you in the accident, and it wasn't your fault, you didn't know them so what you saw was just a body and nothing more, the person had gone and just left a shell. It sounds awful but that's how you will have to see it. You are a caring person obviously otherwise you wouldn't be taking this so hard. I;ve come out of it and so can you, and all here will be with all the way. Godd luck and take care