You can be lonely in a stadium and completely at peace on an empty beach.

Loneliness is about connection, not proximity. A crowd can leave you completely unaccompanied, because people who are not with you sharpen the gap rather than filling it, and an empty stretch of sand can feel like good company when you are not fighting anything. What helps is usually one person you do not have to perform for.

If you have felt alone in busy places lately, that is worth taking seriously and it is not evidence of something wrong with you. Try one honest conversation rather than one bigger gathering. And notice where your own quiet places are, because they are not the same as being lonely.