The narrator's not willing to accept that the relationship is over forever. He's seeking out signs in order to have something to hold onto...for reassurance that he's not a fool for waiting. He's still got faith, and he's willing to put in all the effort in order to regain the one he loves. He's absolutely (happily) determined. He may be slightly heartbroken, but the pleasure he gets from thinking about the future he'll "undoubtedly" have with her outweighs the pain.
The narrator's not willing to accept that the relationship is over forever. He's seeking out signs in order to have something to hold onto...for reassurance that he's not a fool for waiting. He's still got faith, and he's willing to put in all the effort in order to regain the one he loves. He's absolutely (happily) determined. He may be slightly heartbroken, but the pleasure he gets from thinking about the future he'll "undoubtedly" have with her outweighs the pain.