Friendships and Autism 

I understand what you’re saying, we want to do new things but they cause us anxiety. So then we need time to chill out and be alone.

Your startled reaction to the bark reminds me of something. Supposedly, we don't live in the present. We live in our mental model of reality. But there is a catch, it takes most people about a half second to update their mental model of reality to match all the incoming sensory information about what is going on, around us and this updating goes on, continuously. Rather than always being a half second behind reality, we predict or project about a half second into the future, so that our mental model appears to be keeping up with our surroundings. But that only works, when our surroundings are predictable (projectable at least 1/2 second) When something completely unexpected happens, we are jerked out of our reality model and have to reset it to include this new, unexpected bit if information. Being jerked out of being in reality and floating in a void until our new model is ready, can be an unpleasant experience. And that reset shows on your face, when the dog barked.