I love the title of your thread, that says it all.
My personal philosophy is that if you are "trying to MAKE it WORK" that means that it's not the right relationship. The best relationships aren't the ones that you constantly have to work at, they are the ones that everything falls together, you are both happy, you talk, you enjoy each other's company. If you are constantly finding yourself WORKING in a relationship, what's the point?
Yes, it takes effort to keep things spicy, you do have to put forth effort to make the other person happy... but you shouldn't have to constantly WORK.
Find a relationship where there is joy and you will be happy. My philosophy is "when you know, you know" ... I did what you are doing so many times and finally one day it all fell together and I couldn't believe it could be so easy and so wonderful. Then I KNEW.
Good luck.... relationships can be such a headache, but I truly hope you get what you need and want in life!