Dude. A dude who is up to his neck in hoochie complaining about the cost of condoms is a bit much to handle here.
This is a critical and sage question, btw. I've been with the same woman, faithfully, for a couple of decades now. Which isn't to say there hasn't been temptation and second-thoughts along the way. Sometimes, from out of the blue, you never know when you come across someone else who suddenly seems to have a chemistry with you (or at least the way you personally experience it) that can bring the whole thing into doubt and change your worldview a bit.
It's no guarantee of a solid marriage, but I will say this much. You don't marry for love. At least romantic love. That's a recipe for FAIL. What makes you attracted to a person and what makes you a good fit to be married to another person each involve almost entirely different forces or reasons, IMO. I suppose in very rare cases you might be able to suit both. But I'll say for a lot of people the very reasons for what makes a strong romantic attraction to someone can be entirely at odds with what makes them a good, livable life partner.
Romantic love is all about what drives you in attraction about another person at their best. Being married, successfully, can be a lot about learning how to cope and disagree constructively about the things -- often the differences -- that would otherwise pull you apart, and often for how the other person can show you their "worst".
Romantic dating is as much a predictor of a good marriage as watching footie on TV is as much a predictor of your professional goal scoring capabilities.
I think the magic here is in the thinking. You first have to break through to the idea that whether you have a life partner or not, your life is good and you're happy with who you are regardless. Without achieving that first, you're not going to be too attractive and will probably exhibit behaviors that will help repel others.
Spy?
Man, you're getting up there, amigo.

(Says the old dude here.)
Eazy just wrote what I did above pretty much.
Like a male chihuahua.