I just wanted to say HI and tell you that you are obviously not alone
My son is now 16 and it seems like 3 was forever ago. I can only tell you from my experience. Things progress, things change and get better. I remember I was told my son would never know what a cat was or that it meowed etc. He has been mainstreamed since 1st grade and is doing amazingly well.
There is no one that can tell you how far your child or any child will go. The possibilties are endless. I remember thinking am I sending him to the right school, the right class, the right food, the right this and that. It is all a long trial and error journey. You have to follow you gut and your heart. You know what is best for your child. Do not let anyone ever tell you different. I know it is overwhelming. It still is for me. I just know that I am doing the best I can for my child and loving him endlessly.
I hope this helps.