When I got a dx for ds1 I felt relieved that I finally had some answers and that I wasn't just being paranoid, but also very sad that my little boy had SN. It's also hard when the SN (like autism) is invisible because you find yourself watching your child and thinking "but he doesn't look autistic". There's also an element of wondering if things would be different if they'd been dx'ed earlier. When ds2 got his provisional dx and intervention at 2yrs I felt inexplicably guilty that ds1 hadn't had access to the same help at the same age. Completely illogical of course but you find yourself thinking the strangest things.
I think the Earlybird course is for pre-school children but there is also an Earlybird Plus course for 4-8yr-olds and a HELP course.
Getting in touch with your local NAS group can be helpful too. I don't often get to go to support meetings but the group holds lectures/talks about all kinds of ASD-related issues. They also organise evenings out for the families together, where it doesn't matter if your child has meltdowns or behaves differently. The group also sends out useful local info for parents.