Nothing will ever be enough and sadly that includes you. That happily ever after isn't what she's after, otherwise she'd settle with you and work on it, because happily ever after isn't just something that comes with a kiss like in the stories.
It takes hard work and effort to have a happy marriage or relationship, you seem to be wanting to make that effort, but for her to do what she does it's apparent she isn't trying.
Relationships are a bit like football teams, if you have defenders who defend well and attackers who score well, trophies are bound to come. If one half doesn't put the work in, then life has a habit of letting things slip in (much like goals) that you as a team don't want. Think boredom, jealousy, lust and infidelity, verbal abuse, indifference, arguments. I feel like I could probably ramble on more using the analogy, but I won't because I'll just lose the point I'm trying to get at.
I guarantee there's someone out there waiting for someone like you, wouldn't it be a pity if you never found them?