Humans are social beings. We're genetically predisposed to crave human contact. The value of our lives is determined to some degree by those we interact with and how we live within the context of our society.
I can suggest that, although new situation are trying, anxiety-making, and can be even painful, it's worth it. I've had good experiences with classes--learning new things and interacting with people is always beneficial to the brain. Although it's tough, a challenge can help wake up your brain and if you can get through it, it's worth it.
I recommend checking out a local rec center or looking around for adult-education classes. I really don't think the internet is the real solution to the problem of isolation--it may put a balm on the wound, but it doesn't get rid of the problem. If anything it probably exacerbates it.
Try taking up an instrument, and scheduling lessons in a one-on-one environment. Or take up a martial art, or yoga. Or join a book group. Take it upon yourself because, for those of us who do live alone, we must advocate for ourselves. In all probability, if you're waiting to be rescued, the hard fact is it ain't happening. On the other hand, there's no reason you can't rescue yourself.

There is a local choir/singing group and singing is a passion of mine, but I am so terribly nervous as my tendency in groups is to stay off to the side and be unable to go up to people to talk. There was a poetry reading group at the local library and I got as far as getting the contact email of the lady running it to find out times, but never got further.