I could feel your anguish as I read your post. The places my W and I frequently visited I no longer go there due to the many memories. Detaching and in my case forced detachment has been the most gut wrenching experience that I have ever had.
I have been told that there is no timeline for DBing and that a breakthrough could happen at any moment so I will not comment on taking OW on vacation. I do agree that you can only detach totally when feelings for your S are gone.
I plan to continue DB'ing for a while or until I feel that it is fruitless to continue. I believe if you truly value yourself and are truly detached you will realize that there is someone else out there who will value you as well and want to be with you.
