I can certainly relate to you because I have practically no family left, am single and have never been married. I am in bitter and protracted dispute with my place of employment, so you can get the picture.
One aspect, which almost everybody has, is a number of grievances generate in the past. I believe that Fred Luskin in his book "Forgive for Good" is an excellent start to understand grievances and how overcome it.
I think the New History Generator is a good start. You can also get benefits from Anxiety Free, New Option Generator, etc
Look at Happy for No Reason to be used with the book of the same name. If you are happy, you can't feel lonely since you accept what life offers you and be content with it.
