One of the things that you have said here, is that you do not believe that Love is a Choice...
And being a perspective kind of guy, I want you to think about something that opened my eyes a bit....
Do you love your children ??
I mean really LOVE them, with all of your being ??
Is it because of what they do for you ??
Like any other parent, I would say NO...
If my connection to them, hinged on what they did for me ???
Then I would be in trouble...
It is what we give, instead of what we take that fosters our love for another human.
And yes, we CHOOSE to give ourselves to them....
From your posts, I would say that what you EXPECTED, was the fairy tale life with her. You expected your love to foster itself, without having to put in the work. That the elevation of hormones, would last forever, and your distinction between "new" love, and "lasting" love became jaded. New love takes care of itself, and requires very little work.
Lasting love takes WORK, every day, knowing, and fostering those feelings. Building the emotional connection that keeps your partner BESIDE you, not in front, nor behind you.
Yes, you did things for her, we all did things for our spouses, yet we all wanted more. Like I said earlier, unspoken, unmet expectations result in anger, and resentment.
You may very well have been doing those things. What you failed to see, was that you were trying to fulfill her emotional needs, the way that YOU needed them, not the way that SHE needed them to be fed....
Your fix, for her needs....
It also seems that somewhere along the way, you have mistaken love, for obligation....
How would you describe the difference between Love and Obligation ????