Well, to me it means that 'he' has been blamed for problems with 'her' before and 'he' understands that it is going to happen again but 'he' doesn't want to see it happen. 'He' still loves 'her'. 'She' is thinking that 'he' isn't right for 'her', in other words, wants to break up. Obviously, 'he' isn't over 'her' yet. 'He' want to be with her ALWAYS.

I love this song, :D its the story of my life.