Hang in there. I'm a lot older than you and still sometimes feel awkward or unworthy. Yet maybe consider to join a book club or some other type of local club where you will eventually get used to some familiar faces! After a month or two, despite your shyness, you will know some people's names and they'll know yours. It's not hard, things just take time. You feel like you don't know many people now, but someday you may. Relationships can't be forced, just like you can't force a plant to grow. One day, you will turn around and will have cultivated many friendships and acquaintances from joining different activities. You may feel at first that you are on the periphery of a group, and later realize you are part of its inner circle, or even be asked to run it. No one is there to judge you so allow yourself to be welcomed into whatever you decide to partake in!
But just now, for today, or this week or month, no one can make you speak or take action, you choose when to do this, and whether you'd like to, it's up to you. So be yourself, and when you are interested in something is when it's easier to engage in it. If you want to get out and meet people, and have them know you as well, sometimes it is good to join something that meets once or twice a month that is a more physically active group, like a gardening club or community clean-up or building group. This way, you have a reason to do something novel plus ease into being more social because you will be there to learn something and to keep active. This is an opportunity to get out and make yourself known to others and also you too will recognize more and more people from your community, until you'll be walking on the street one day and realize you know half your town. It might be best to join 2-3 different local groups that meet, each a few times a month, to really see which ones you like. Maybe you think this sounds overly optimistic given your predicament, but strive to give these some chances. These are just ideas but something easy to try! You are not to shy for this, I promise!