I don't think this is just about not tainting a new relationship with past experiences. There is an element of reviewing a relationship that is dying or is dead. At the beginning when she talks about "going backwards in time...I'm yours, you're mine...not alone" and the "freeze frame" both are reflections on the old relationship that started the same way, but it won't be allowed to shadow the new possibilities. "Don't let go Don't you let me go" is the heartbreak of the old relationship ending. The first verses are the past experience warning, the chorus is like the breath before you dive in and the second verse is the 'spark' of the new beginning.
I don't think this is just about not tainting a new relationship with past experiences. There is an element of reviewing a relationship that is dying or is dead. At the beginning when she talks about "going backwards in time...I'm yours, you're mine...not alone" and the "freeze frame" both are reflections on the old relationship that started the same way, but it won't be allowed to shadow the new possibilities. "Don't let go Don't you let me go" is the heartbreak of the old relationship ending. The first verses are the past experience warning, the chorus is like the breath before you dive in and the second verse is the 'spark' of the new beginning.