I genuinely don't understand what there is to be anxious about?
It's not like this is a real over-the-board chess club and you have to face the other player, look him in the eyes and say "I resign", whilst a crowd of people watch you lose.
You're playing online against some random people from other countries who have no idea who you are and will probably never see you or play you again. There's millions of users on this site, so you're pretty much invisible.
Whatever games you win or lose - however much your rating changes - only you will notice and only you will care.
I think the anxiety is all around what @Brad253 pointed out...
As a begginer you might think that chess is directly related to how smart you are, and of course that's kind of related, but for an amateur I think the fear of losing to a real person is related to a fear of having a "proof" that he/she is not smart.
It's very commom to see this "self sabotaging" behavior (seeing problems before even starting to deal with the situation) in all kinds of situation, so it seems preety normal to me to see it on chess.
I genuinely don't understand what there is to be anxious about?
It's not like this is a real over-the-board chess club and you have to face the other player, look him in the eyes and say "I resign", whilst a crowd of people watch you lose.
You're playing online against some random people from other countries who have no idea who you are and will probably never see you or play you again. There's millions of users on this site, so you're pretty much invisible.
Whatever games you win or lose - however much your rating changes - only you will notice and only you will care.