I like your hook-as much as I dislike economics/math, this drew me in because I have never thought of relationships in this way.

Maybe add a bit more to your "Game Plan" section. I'm sure readers will be taken aback when they hear that passionate love won't last in their relationship. So maybe give some examples for your advice. For example, for "seek new and engaging ways to have fun together," perhaps list off things like: go on a little trip, go wine tasting, etc.

I like the color scheme and layout-I didn't incorporate this into my own blog, but it makes it more aesthetically pleasing.

I like how you start off with a good hook to draw me in-I've never heard that love doesn't actually last forever, or not in this sense. I'm definitely interested!