We had a lot of issues with our son when he was this age, including the issues you describe. We were very frustrated for a few years. I strongly considered the possibility of autism at the time, but ultimately dismissed it because he had ridiculously good verbal skills, was fine socially, made eye contact, and was missing a few other stereotypical traits.
As he has grown (and as I’ve learned more about autism) it has become more and more apparent that he is likely on the autism spectrum. To be clear, we do not think that is a bad thing AT ALL. We never mentioned autism by name to my son or to his doctors directly, but we did talk about “sensory issues” and “struggles reading other people” and “difficulty with change”. We have helped him managed his issues a la carte and he has thrived. He is kind of a weird kid, but is fantastic in school and work and has plenty of friends. All of his odd traits are pretty much charming to us and are just part of his awesome personality.
But when he was at the children’s hospital as a teen, several specialists picked up on this (he is literally hyper-reflexive) and said something to me about it. Coincidentally, on one recent drive to the hospital, my son (who is now 16) kept bringing up some of his issues (including light sensitivity) and saying, “you know, that’s a sign of autism”. I told him that yes, he was correct, and that I wouldn’t be surprised if he was autistic. He asked if we’d ever thought about getting him evaluated for diagnosis. I told him we’d be happy to do that if he’s interested in receiving a diagnosis and thinks it would be helpful.
I plan on following up with him about this before his next checkup. Getting him diagnosed is not important to us since it wouldn’t make a difference in his care and doesn’t change how we see him. But I can definitely understand why it might be important to my son and totally support him wanting to know. It might have made a difference when he was younger, but we wouldn’t have really done any different treatments than what we informally did anyway. A lot of “treatment” for autistic people is actively harmful, so I don’t feel like we missed out on much there. Just wanted to offer my perspective as a parent of a likely autistic child who has thrived with our informal accommodations.