Economics aside, it seems like part of the problem is that many people your age already have families, and you're now unsure how to make friends who are your age. One thing you could do is seek out people in a similar situation to go to the festivals with, or to go to bars with, or on trips. And if you should happen to meet a bunch of 20-somethings who want to get to know a 35-year-old, then why not?
Either way, you should probably ditch the idea that opportunities are somehow unavailable to you, and instead focus on how you're ready to move on to a new stage of your life. Whether that stage will involve career changes or travelling or moving or anything else will have to be your decision, but it sounds from what you're saying like it may involve building new friendships.