All i can say is keep trying - friendships don't happen overnight and in these times there even harder to keep going (people having to get second jobs/work longer hours and then come home to kids and a partner who also need their undivided attention). Its tough but it is doable. Are there any other classes/groups you can join? Even if you don't go with the intention of making friends, just chatting to new people can build your confidence and help you to relax more in the company of strangers. If you find your hitting a brick wall i would try occupying your attentions with a challenge - try learning a new language or an instrument even, not only will you be improving yourself but you'll be using your time constructively and hopefully distracting yourself from any overwhelming feelings of loneliness. Either this or you could try being a little more vocal per se on facebook. It may seem superficial or even futile you do have the power to make more of your current contacts you just have to keep at it. Good luck.