I have most of the same symptoms you have, and I am 40. I was never diagnosed with autism, because it was very rarely diagnosed when I was a child (before 2000). Plus I have a high IQ and got good grades. I struggled a lot socially, but teachers never saw that. In the US, it is tough and expensive to get a diagnosis as an adult. I checked, and my insurance only pays for diagnosis in children.

However, I have been able to get support even without the formal diagnosis. There are virtual groups through Asperger / Autism Network (AANE) We are here for you! you might want to check out. I told them I didn't have the official diagnosis, and they still accepted me and let me join the groups. I'm in one now for women in mid life (40-60). I find it very comforting to listen to others with the same story I have.