Waiting

You led me to believe That some day we would be More than a question mark Or possibility

[She's in an extremely confusing relationship, whether it's friends with benefits or a relationship that is going nowhere. ]

We're living in denial 'Cos this just can't be true I'd still wait all my life To die right next to you

[They're both in denial about their failing relationship. But she knows that she still wants to be with him forever.]

I'll be holding on another day Don't know how we gonna make it But I know we can make it alright All I know is there's no other way Don't know how we gonna make it but I Know we can make it alright

[She wants to give their relationship another chance. She knows that she can't (or won't) walk away from it. She also realizes that it's pretty hopeless at this point, but is optimistic.]

This ain't no sweet surprise This love was filled with time There's such a happiness I feel it, it's alive

[Even though their relationship is hopeless, they both feel a sense of happiness with each other still. They spent a lot of time building the relationship to where it is.]

At the moment, I feel you in my heart Yeah, I feel it I don't know where to start Gotta get this ball rolling But I can't control it If I can see it, still believe in

[She can still feel the love she has for him. She wants to repair their relationship, but doesn't know how to 'get the ball rolling'. She feels that as long as she can see/feel the love she has for him (and vice versa), she still believes in their relationship.]

Also, note how upbeat the song is. It fits perfectly with what she's trying to say. Their relationship is hopeless and everybody else sees it, but she refuses to give up and is hopeful that they can work things out.