First - stop being so hard on yourself.

You are doing the best you can, and that's ALL you can do. You and your family are all in this together and you sound like you are trying to take it all on yourself. Doing therapy "all wrong" is relative - some things will work for some kids, some other things will work for others, which is part of the insidious nature of autism. You are not an 'idiot' - you are in the same boat that we all are, trying to find a good balance between allowing your son to be himself and helping him gain the skills he will need to interact with the outside world, a tall order even for parents of "NT" children.

That being said, I can only speak from my experience in the State of Nevada regarding affordable therapy. We have been very fortunate with a state-sponsored early intervention program, where I was taught how to work with my son and he met with therapists about five times a week, and the school district took over with an ABA program when he turned three. All of these services were free, and, in the meantime, I was able to research support programs through private and public foundations and am currently working on applications for services from said programs. I guess my question to you would be - does your state have any such program? Has your son done and IEP through the school district, and, is there a program there that will meet his needs?

All of this is incredibly overwhelming, especially when you feel like you are going it alone. Most places have programs in place that are designed to help people in your situation. Since I don't know where you are, I can't tell you specifics, but you might start at your state Board of health care. Most people will sniff and say that those programs are not adequate, but hey, it's a start and you won't be trying to do it all by yourself. You might have a local support group, too, that you don't know about.

You have voiced things that have gone through my head as well, and I can only say that reaching out to local groups has helped me enormously. They won't have all the answers - no one does - but they can help you reach a peace with yourself and enough will to carry on. Your son will benefit more if you are not so overwrought. As you say, he needs you, and your entire family will be in a better place if you aren't constantly punishing yourself. Hang in there - this is a process, not a goal.