Numbers don't make one great, though. If God inspires you to help even one life, you did a great thing.
Paul Chavez
I recommend reading Neurotribes by Steve Silberman. It shows the history of autism in the medical profession (WARNING: rife with racism, ignorance, and con artists) and recommends we admit there are more ways to think about things than just Neurotypicals. I am most likely on the spectrum but never diagnosed and my boyfriend lives in a group home with autism and cerebral palsy.
1. Don't lose hope. If he's nonverbal, there are now plenty of communication options for him, like iPad apps and such. If you find the right communication tools, a lot of the tantrums should reduce, as most of the time it is just frustration from not being able to communicate wants. Even basic made-up sign language is more helpful than just insisting he speak.
2. It's not anyone's fault. I suspect it's a mix of environmental and genetic issues at play, with each individual susceptible to varying degrees. No one makes anyone autistic, though heredity does seem to pop up on the radar (kids with poor socialization abilities and hyperfixations on certain topics tend to come from parents with the same issues).
3. Life is weird, sometimes.
4. Could be a host of different reasons. What matters is not what caused it, but what we can do about it. If you are on Facebook, I recommend looking for neurodiversity groups (definitely avoid Autism Speaks, as they are con artists with a dark desire to "cure" [read: eradicate] people on the spectrum because they/we don't measure up to their ideas of perfection). I think it would definitely help to speak to actual autistic people, people who've grown through it.
Not all of us bang our heads against the walls and mumble and wet ourselves and such.
Struck me as a lot older
Dunno if these links will work, but...
Neurodiversity Book Club on FB (I think this must be a closed group and requires someone to give you access)
AutismHWY on FB
Paul Chavez, I know we haven't always agreed on everything (understatement), but now that I know about some of the things you're going through, huggles!