Glad to find this site. About two years ago I had so many friends that it was great. It was at my last job. But then, hundreds of us got laid off/fired. Only a handful of folks kept their jobs. It was a wonderful company and I miss seeing my friends each day.
Although I try to keep in touch, none of them seem to miss me (I miss them all terribly) or even want to get together. They've all moved on, got other jobs, got married, moved away. Also, two long time friends of mine got married and now are no longer interested in hanging out with me. It's embarrassing at my age (52) to be friendless, yikes!
When a business undergoes mass layoffs like yours, it can create a great deal of chaos for those who are laid off as well as for those who are left behind. Many people may have residual hard feelings for the company and may not want any associations with their former colleagues.
You say that many of your former friends have had significant changes in their lives since they left, including new jobs, new marriages and new homes. Changes like these can be disruptive to friendships although they aren't necessarily deal-killers. It sounds like you are used to making many of your social connections at your place of employment, which is understandable given the amount of time people you spent there.
You are now in a situation in which you realize you want more friends than you currently have. Given your desire to have more friends, you need to find ways to meet new people -- whether it is at another place of employment, your neighborhood or as part of some other organization. Do things that are interesting to you and maybe you will find some kindred spirits. As you learned in your last job, seeing people daily makes it easier to bond.
Now that the dust has settled, you may also want to try to resurrect some of these old friendships again. With the passage of time, people may have gotten on their feet finally and be more open to reconnecting. For example, you may want to reach out to friends you felt close to who are married or who moved to another town. You may not have the same type of friendships with them that you once had when you saw them day after day, but you can develop different types of friendships.
Most importantly, do not be embarrassed about having no friends! That can pose a tremendous psychological barrier that prevents you from reaching out to others. Remind yourself that there are many people in the same situation who want to find friends as much as you do.
Hope this helps.
Other posts about making friends: