Such a good question ! The feeling of comfort, return to childhood/babyhood, at least the feeling of it, are difficult to separate from sexual pleasure. Sometimes, yes it is sexual in part for me, but not always
I do sort of understand. Could not say about autism, but I suffer from depression, and tend to turn friends away. Also tend to "chicken" out of social events and later regret it. We are what we are, and I hope you do find a friend or friend who can stick in there. Take Care. Rich