What confirmed your own autism suspicions?

Hello, I am very new to all this, so please forgive any faux-pa's I make regarding post-etiquette. 

I am awaiting autism  diagnosis on the NHS. I have read up extensively on the classic signs, but I am curious what specifically confirmed it for you.¹ I have made many analogies to people over the years, as I have struggled to find a cause for what I believe is behind my decades-long battle with anxiety and depression. I am 52 years old

It is like you are walking around in a big spacesuit. You can perform basic tasks but are unable to interact with people on an intimate level. They see you, but are unaware you are in this suit. It's frustrating, as you can see people living their lives, while you can only watch. 

This is the best description of how I feel and it is a desperately lonely place to be. I often contemplate the point of it all when It seems an impossible problem to conquer in an ever increasingly complicated world.

Apologies for the ramble, but it would be nice to know I'm not alone.