Please DO NOT feel bad! My son was diagnosed at 2 1/2 with PDD which is Pervasive Developmental Disorder, it is also found on the Autism spectrum. I was 7 months pregnant with my daughter at the time and was scared to death. My husband works in the MRDD field and I am a teacher. Neither of us had ever even heard of it before. I immediately grabbed as many books and websites that I could and began a frantic search for answers. I would sit and cry everytime I read something, I found that after learning basic information I could use common sense to help my son. I enrolled him in speech and occupational therapy, got in touch with our local MRDD office, Help Me Grow and our local schools for ECSE programs and starting using their help.
I was very angry at first which then turned to self pity and then frustration. Once I realized that what we have is a gift, and that things could be so much worse, I put on my big girl panties and sucked it up. My son is now 4 1/2 and is very intellegent and happy. We still have daily struggles with meltdowns, but we deal with it and move one.
With a referral he should be able to start therapy, you should sit in on these if you can. I found it helpful to see some of the ways they worked with him, and I then carried over to home. Then get in contact with your local Disabilities organizations, they can help you financially some and refer you to other local organizations.
I hope this helps. I am still learning the ropes too! Hang in there.