I don't understand what your therapist is stating. If you grew up with "nudists" then being nude would NOT be an attention-getting go-to. Putting on a ball gown would be attention-seeking.

You may need a different therapist.

You also should know that this may not be a "forgive" type error you made. His friends have now seen you without clothing. Many men don't care for that. It might be a dealbreaker for him. It would be for me.

There is something deeper happening with you, because a way to get attention during a video call would be to talk during the call, appear (clothed) in the video, or some other thing. Definitely not deciding to take your clothes off and parade in front of the camera.