I'm supposedly fucking up a friendship I had
Do you still consider the person your friend?
I've known the person since childhood. I've been travelling together with him before, we played a lot of games and we did a lot of stuff together, he was my very good friend
If you are no longer friends, you should just move on with your life so that people don't accuse you of messing up a relationship.  This friendship sounds like it's getting toxic, so you two should go your separate ways to avoid further drama and stress.
I didn't do anything that would make us not friends. I just can't understand why this is not working for us anymore.
I would just let it go. The reality is , is that not all friendships will stand the test of time.