Man.
I know exactly what you are going through, I had an ex who, at the end of it all, was just not compatible in any way with me except in bed. Despite that we were together for years and I just took it for granted that she could come vaginally, clitorally, g-spot, over and over... I was a multi orgasmic male and she was a very multi woman. Any fight we would have would be patched up by an all night screwing fest that would leave us spent and basking in the post coital glow. We could both go at it forever and it was never 'work' to make her come, and she never felt like it was a hassle to satisfy me, it never felt like trading or reciprocation or whatever, we were both just cumming over and over as we went at it naturally.
It takes two to create that kind of chemistry but with some people it is just much harder than for others. You can still have a loving, rich relationship, but it's tough when you've experienced the other way...
That was a long time ago, and since then, I've learned that some women do take extra attention and even then it's not a given that there's going to be an orgasm. Thing is you don't get to find out about what she's like orgasm wise until you're pretty well into the relationship. My current partner loves me 100% but she just doesn't come without 10 or 20 minutes of oral. I don't mean to sound harsh but going from come-O-matic woman to come-once-a-month-maybe is very deflating to the male ego and I feel like my skills are being wasted.