You're on the nose:
I'm only obsessed when we aren't having sex... otherwise I'm not-obsessed. I tried to explain that it was like food: if you are hungry but all you get is 1000 calories a day, you're always going to be hungry and all you will think about is where to get your next meal; people might say you are "obsessed" with food. So it makes perfect sense to think about the thing you want that isn't being had.
In one argument I tried to explain that I'm not just looking for more sex... I'm looking for "better" sex. That didn't come off well because then, once again, she wasn't good enough. So I rolled wroth that and said, "no, as long as you seem disinterested in sex both when we aren't doing it and when we are, then no, you aren't being good enough. If all I wanted was "more" sex, I would have simply divorced you when it was coming to that and had sex with any number of viable, willing participants. But see, that's the key word: "willing.". You don't seem willing, you just seem to settle on doing it with me... and I'd rather have sex with you then anyone else, but not if it's like having sex with someone who doesn't like me."
That argument ended in pretty good sex that night.... but that was an early argument.
She has stated that sex isn't as important to her as it is to me but maybe that wopill change in the future.
A marriage can't be built on "maybes."
After we reconciled it was high-energy, adventurous sex, for 2 weeks straight -12 days out of 14 and 14 times total. Then it fell off precipitously (once every 4 days on schedule.). The times in between had no fire or excitement, -she had no apparent desire to flirt, touch, nothing, then sex initiation was a touch in bed as a signal but she will just lie there and I had to do all the "work.". Eventually we would argue about how I still don't think she's into me and it bothers me and makes me feel bad. Then sex would be good again for a week, then the following week would drop off, and then the third week I would show signs of depression and we argue and then begins the cycle again. We've been in the cycle for some time now. Holiday schedules and travel has sort of disrupted it, but it's still there, waiting to turn the wheel; again.
We have 2 kids. They do hamper things, but, see, the issue I've always had was one more of quality and not quantity. I understand life happens and kids are a pain, sex-wise, but when we can't have it, I tell and show her how much I long for her and to be alone with her; that even though life is in the way, I still will muster all the energy to make sure I can satisfy her. She seems to take it or leave it and when we do do it, it's ALWAYS normal sex (the stuff we know works on each other.). Anything else is a chore for her and I'm the one doing all the "work.". And all I really want is happy, fun sex where we both ask stuff of each other and explore each other, because if we can't have a high quantity, a high quality could make up for most of it.
If we had it 7 times a week and it was regular, normal stuff with no variety, I would still complain. As it is, 2 good times a week is adequate for me but I would never tell her a number because I know she would just settle on that and it would be 2 normal, days of sex; I feel like I need her to guess, to be unsure and under the impression that things are, like you said, unstable. But you and I know this isn't long-term tenable... I know it because now arguments don't make for good sex anymore and we have both said we are tired of having the same argument over and over again and the arguments have less fear to them... they've gotten more and more angry.
So like you, I've begun to "settle" into what I have... I have rules I set up to make things happier for her:
All added up, I basically have to wait for her to initiate, and when she doesn't I start to get depressed and feel unwanted.
So I can't tell if I'm the bad guy or she is any more. I don't want anyone to be, but something is wrong so someone must not be doing something right.