Backstory: I have a really hard time socializing and connecting with people. it is incredibly rare I find a friend that I connect with, like I dont remember the last time it as happened wih the exception of my e friend I will call x

He means so much to me, he is honestly the most kind and understanding person and I really love him. We live in different countries but he is my best friend, the problem lies with my anxiety. 

I am so scared of losing him, I had a panic attack earlier because I was so scared he would leave and get boerd of me and I will be all alone, this isnt his fault at all, he is so loving and caring but you know how anxiety is. Here is an example of my anxiety thought process:

"He takes a long while to reply? Well that can only mean you are a boring and annoying person that everyone will just leave and then you will die alone because nobody loves you, you will have nobody and be sad and misreable"

How can I not be anxious over this or at least cope? I am unable to get therapy at the moment, thank you