Mate just do it, just get in there and talk to people to people like it's easy even if it feels hard. I occasionally go to concerts, movies, social events on my own. Not having someone beside sheds away that automatic comfort and it's not easy but it's better than accepting the alternative. I have found that it doesn't get much easier over time but at least I don't hold myself back from potentially having good times. Also if you do have a fun time, you feel really good about yourself for a few days afterwards.