My son is three. And I felt the same as you getting his diagnosis. I still cry sometimes. But… he has been in aba for about a year now. He does 2 hours a day of aba and 2 hours at preschool. The four hours total have been great for him. He has made some improvements and behavioral changes as well since we started his school and therapy. I would say over all aba is very beneficial and even if they offer you 8 hours you don’t have to do that many. I was offered 4 hours of school and 4 hours of aba (both 5 days a week) and I just split it so he could do both. It works perfect for us so far. Hope this helps.
My son also just got diagnosed and they’re recommending ABA, private speech, occupational, and physical therapy. They’re recommending 25 hours of therapy a week. I’ve heard mixed things about ABA but I don’t have an opinion myself. My son is also 2.5, he’ll be 3 in July. If you ever want to talk to somebody feel free to message me