Easy to say 'get out there' I know but that is the only way to improve your life. Perhaps communicating with people you know via the internet. Alternatively contact family members. You near neighbours might be glad of your interest in them if you give them a call. Another thing which can bring change and happiness is a pet. Why not get a dog? So many people have met and become friends through meeting whilst walking their dog. Perhaps you might decide to buy a morning paper so a daily trip to your newsagent will mean contact which might lead to friendship.
Open you mind to change it is the only way to a brighter more interesting life.