I think learning to trust another and let down defenses is a process. And it's not always linear! Sometimes I'm very open and trusting, and sometimes I go backwards and I'm totally closed off.

When you ask if this can be fixed with therapy - do you mean can your defensive be fixed? If you don't think you're defensive, why would you want to try to fix it? Do you think it would help to figure out a different way to relate to people? That is something that can be worked on in therapy.