Any success stories after your child was diagnosed as Level 3?

just looking for a little bit of hope. my son just turned 3 and was diagnosed w/ level 3 autism 6 months ago. he's still non verbal but has some signs and points to what he wants, he makes noises to signal what he wants and is babbling. we've had him in all the therapies since he was 18 months old and its very slow progress. just looking for success stories from others who got a similar diagnosis