I can't answer that, truly... since every situation is different.
Sometimes, we're hurt by the ones we love. Either intentionally or unintentionally, whether because it's wanted or an accident...
Sometimes, it's because they think it's best. Or better. Or it hurts too much for it to be any other way.
For those who are hurt... it can be forgiven or it can not be forgiven. If it's truly unforgivable, truly something that is too horrible to accept, or the person we love has changed too much to be recognizable, then... sometimes what's needed is to be helped. Or to understand it isn't your time and place to do so, to understand that taking care of yourself is important, too.
But everyone is capable of having a happy ending, even if it isn't the happy ending that's expected -- even if it doesn't seem like a happy ending at the time. That just means it isn't the end yet. It just means... there's still time.