Preventable is different than on purpose. Whoever was responsible or didn't prevent this tragedy...did not want the child dead....on purpose.
So many documentaries tell us that holding on to anger makes US sick.
I have never been in a similar situation so I really don't know how he is feeling. But, I do know what you have told us is that psychiatric help is not an option...and honestly I keep thinking that...you are trying to heal and he is pulling you down.
8 years is a very long time to try and compensate for someone elses anger

.
I personally would have to end my marriage if this was going on in my life. Life is too short for living in discontent. I don't know how much your husband loves you...but maybe if you made a move such as a seperation that would wake him up from what is NOW important in life.
No one can bring the child back...and no one can change someone elses mind...now its up to you to decide how you want to live the rest of YOUR life on this planet...
__________________
"I'm not crazy, I'm just a little unwell"
(My girlfriend had this ringtone for my phone calls...lol)
Bipolar 1
Anxiety
Current Medications:
Lorazepam
Zoloft
Abilify
Gabapentin