Welcome here and I'll get straight to the point. you asked for validation for what you have been feeling is normal.
The answer is no, far from it. Life is for most, while not problem free, well worth living with things to enjoy and look forward to.
It is a great pity the car crash put you back just wjen you were starting to improve a little. The symptoms you describe seem to me similar to some of the thing I've had with PTSD and depression including nightmares, inability to sleep, eat & feeling restless and getting angry easily .
So I'm no doctor, but might I suggest you go see one and in a long appointment explain your past history and your current state.
I found that competent medical help made all the difference.
As far as personal support is concerned, is there anyone you can lean on at the moment? Friends or family perhaps? Trying to face all this in isolation is very hard
I hope to hear from you soon