I imagine you've already paid DearDebra, but I'll add something anyway. 4 years without getting married is more than the 3 years that it normally takes for the initial passion (biologically generated so humans will stay in love long enough to generate and wean at least one baby) to simmer down. Then the differences that have been somewhat ignored grow like weeds and the motivation of passion to cope with them is often way weaker than one expected, and more so for one partner (the man, who since the 60s cultural shift to sexual freedom-from-marriage can be more responsive to his sexual feelings than before). In cultures world-wide where divorce or separation is easy the most common years for sep/div are yr 3&4 of getting together.
So in gross generalization, that's what has happened to you. Debra was advising you about approaching and withdrawing. But the crude emotional reality underneath this directions is this: The person who's more willing to leave the relationship always has more power than the person who want to restore it. Called Pursuer/Distancer Dance, with the Distancer having more power. So when you backed off or issued an ultimatum, he'd pursue you, but once you wanted back in, he'd back off: and that's because "New love chases away old love" because the passion level is still high.
For women like you Morality usually plays a bigger role, because women aren't as much driven by passion & particularly sexual passion--since they're responsible for raising children and that leads them to naturally achieve a broader view of the relationship than just how "hot" it is in the bedroom. Yet passion kicks in to prevent the partner from leaving, so the Distancer does ignite passion in his (or her) partner, even if it's not so explicitly sexual.
Bottom line: You're right. It's Over. And you're not alone in this experience at all. And beware: Breaking up and reuniting reignites passion and can keep you breaking your heart several times, until it hurts more to be together than to be apart. But our emotions are designed to recover from such painful "brinksmanship." Your new day will come, and later, New Love as well.. But keep your eye out for Roller-coaster Love (as a habit-forming version of Brinksmanship), because the added excitement&fear isn't worth the more enduring repetitious hurt.