Yes, I also talk to myself for much the same reasons as you state. I have always been a loner, even when I lived with relatives, but now live alone, so there is no one to talk to here. Also, I find it does help me to think if I talk things out to myself. I also make comments to the radio or TV, again as part of thinking things out, and as a means of expressing my opinion in my solitary existance. I do occasionally talk things out quietly, when away from home, also. When I was a child I was taken to many therapists, and shrink docs. None of them ever helped me, but I found that I did absorb their techniques, and eventually started doing my own talking self therapy sessions. I prefer that over talking to these strangers, who I have always strongly sensed don't really give a hoot about me. I always felt it was just a paying job to them. Sure some of them did want to have successful outcomes, but that was to make them look like they had earned their money. I always felt that they were trying to mentally violate me for no good or useful purpose, with their intrusive questions, so I never fully cooperated with any of them. Occasionally I just got fed up, and would totally refuse to cooperate, leading to switching to a different shrink. Unfortunately, back when I was a kid Autism and Asperger's hadn't been identified yet. People on the spectrum were often diagnosed with emotional and/or behavior problems, plus sometimes other things, as well. If you have emotional or behavior problems, then you can eventually learn to control and change to better behavior patterns, but that doesn't work for people on the spectrum. But since our condition wasn't identified then, we were considered to be problem children, who were being deliberately difficult. I had to work out my own coping mechanisms over the years, to deal with my Aspy traits, without even knowing what Autism and Asperger's Syndrome were. Finding out about Asperger's was a big relief, because now I know why I am so different from NTs. I know it doesn't fix things, but the not knowing left me feeling like I was some kind of freak, instead of what I am--someone with a medical condition that I've had since birth.
There is no cure for people on the spectrum, but there are coping mechanisms, and some people are helped by medications, like anti depressants. I prefer to avoid the meds, because of the potentially dangerous side effects, so I just use my coping mechanisms, including talking things out to myself. So don't feel you are really weird for doing this. I've heard that many NTs do it too, for the same reasons, and I've encountered a number of people doing it quietly in public over the years. Only twice were they mental cases. One was an older man with a mild mental case. The other time occurred when I had to stay a month at a Salvation Army shelter. One Saturday morning while I was there, a young man who was also staying at the shelter, was outside by himself having a violent argument (by himself) with immigration authorities (who were not there) about his girl friend--who was apparently in custody as an illegal alien. He was also discussing some really weird other things. I had to go past him to leave for the morning, and made sure not to get too close, and I did not try to join in his solo conversation, or other wise try to interact with him. I heard later that the shelter staff had to make other arrangements for him, because they're not able to deal with mental cases.
Don't fret about talking to yourself--you don't come across as a nut job, just someone who is helped by talking things out to yourself, and everyone is entitled to this simple, do-it-yourself help. And remember, we on the spectrum are all:
A Different Drummer
If a man does not keep pace with his companions,
Perhaps it is because he hears a different drummer.
Let him step to the music which he hears,
However measured or far away.
--Henry David Thoreau