This brought me tears because you are obviously a wonderful mother. You made sure to help when you could while dealing with the stress of it all and working!! You didn't fail. You are a human being and we can't be perfect. Most of all, you CARE! That says a lot.
I know all too well about this though and where I beat myself up about things, too. I guess that is just human nature, huh?
One of my best friends is a special needs teacher and she has these meetings all the time that she tells me about. She loves meeting with parents like you because she deals with some doozies!! Is that a word? Who knows but I think you'll understand my drift.