I told my best friend I loved them and ruined everything
Did something in your childhood teach you that it was bad to tell people you love them?
No, not really, my childhood doesn't really have anything to do with this situation.
If you feel like you made things awkward between you and your friend, then you should have an honest conversation with your friend. Explain what you meant, and apologize if you said something that made them uncomfortable. The best way to work through awkward situations is with honesty and forthrightness.
I think that I might just avoid the topic for the rest of the time that we are friends.
I think that you should have the talk and just get it over with. It is good to tell your friends your true feelings for them.