Why don't you go to an AA meeting? Everyone there understands what you are going through.
I know I got to the point where you are by the end of my illustrious drinking career. None of us go into AA on a winning streak. I didn't trust anyone, I didn't have any friends - just acquaintances. I knew everything and everyone annoyed me. I live alone and do my life alone. It seriously sucks. Since I've been going to meetings I've slowly begun to come out of my shell. It didn't happen quickly but no one pushed me, either.
I've also started looking for outside activities other than walking. I've been spending time in a bookstore, I've gotten numbers for bird-watching groups, I've gone out to lunch and breakfast with people from meetings. I go to the zoo once a week and make sure to talk to people there. I am thinking of joining a hiking club. It doesn't happen all at once, but I have to start somewhere.
I agree that some people are not going to understand, but in time they will see new behaviors and be happy that you have made this change.
You are exactly where you are supposed to be today. I hope you enjoy your walk, sounds lovely.