A dosage of harsh truth: if you gave yourself half the love you've given him, you wouldn't be in this mess in the first place.
You might tell me love is unselfish, or love is unconditional. Bullshit. This is the time for you, for once, to be selfish and self-centered.
It's time to stop making this about him or what he's done (or what he didn't do). Stop allowing yourself to be weighed down by an inconsiderate, unappreciative person.
It's about you now, and what you need is—well, you'll have to figure that out for yourself. Do you need distance from him or time away from him? Find out, and give it to yourself with no guilt or hesitation.
Right now you feel that every day is a sink-or-swim scenario where you struggle just to keep your head above water. I promise you that it gets easier. It'll be over.
And I promise you that when this is over, you'll discover that you've emerged as a person a thousand times better than who you once were.
For one of my best friends, whose courage and strength continue to inspire me every day.