What am i doing wrong?

My nearly 15 year old son is acting out.
He has autism/asperger syndrome, blah blah blah.
I have always taken 100% care of him, above and beyond.
He is acting out. At home. At school. Everywhere. Except with his "dad".
I have "stepped it up" recently (or at least I thought I had)
More doctor appointments.
More medicine changes.
Now in therapy.
Talking to the school constantly.
He told me tonight I am the reason his life is miserable.
I know he's just a kid. A special kid.
But words can hurt.
I want and need some support with this so bad I can't even stand it.
I feel alone.
It's affecting my job.
It's affecting my marriage.
It's affecting my daughter.
It is affecting ME. bad.very.bad.
In a perfect world, my spouse would be supportive and non-judgemental of me trying deal with my special needs child.
In a perfect world, there would be some type of support for me.
In a perfect world, I could fix Josh. I have always figured things out. Not working for me this time.
And then there's always the ex, my son's sperm donor.
Always positive and helpful telling me how "shitty and pathetic" i am with my mothering skills.
Just the boost i needed.
I feel like a failure at this point in my life more than any other. and that is saying ALOT.
What am I doing wrong............................