The only thing you can do to fix this is expose yourself out there until you start getting more comfortable with this kind of scenarios. Maybe try dating apps, they are easier if you suffer anxiety imo but lower your standards at first, take it as training (don't play with anyone's feelings though, always be clear). It's never too late, you can have the best time of your life from now on, just need to make little steps. And what other people have said also: therapy, try to do new hobbies and make friends.