I know guilt tends to stop me from doing a lot of things that would otherwise lay heavy on my conscience.
The other day I happend to hear this.... you may not "love" or have feelings for your spouse but ACT like you do. Don't push it. Just try to be natural and act as if you do and think it. Often it's the actions and thinking a certain way that will bring about the feelings.
I find if I try to think more positive I become more positive. Hope that's helpful. And yes, biochemicals seem much more potent than just trying to behave and think a certain way. But... babysteps...
There is no arriving, ever. It is all a continual becoming.