Sex and my wife's inability to change

My wife is JUST now getting diagnosed but the more I read the more I understand that she is ADD and how that has been killing our marriage.

Let me start by saying that I have a high libido with a proclivity for being a thrill seeker. My belief is that thrill seeking is not bad as long as the activity is within norms... E.G. a sex swing in the privacy of our bedroom.

My wife is a comfort creature and has ADD. What that fleshes out as is very boring sex that can have gaps of weeks between intimacy. I am the first to admit that I can't have my own way, but I believe that sex, like anything must be a compromise. The problem we are having is that any request I make can be discussed and agreed upon and sometimes with excitement on both of our parts but within a few weeks, it's as if we never had the conversation... at all. Even after we have had a conversation hundreds of times, she can look at me as if this is the very first time she has heard it. 

I get that it can be part of the ADD brain and you feel like a broken record, but she is VERY combative to ANY type of coping mechanism. I have read that lists help, so that reminders aren't nagging. But, she gets irate over lists as well. Anything I ask her to do becomes a fight. It could be as simple as asking to have dinner at a regular schedule... I completely understand that I will have to help her manage the ADD and get this to happen, but he idea alone is a war!

How do I cope with this. I have to be able to bring life into some sort of functional stasis but she refuses to even  let me help. 

When it comes to sex... forget it... I can ask a million times for sex to be something I like 50% of the time and she will agree and also say that she likes that as well... but then nothing... nadda... and two weeks later, she is back to behaving as if we never talked. That I can understand... but then she refuses to understand that I am pissed and need her to at least admit it's the ADD.

That alone is enough to send me packing. But for the sake of argument and hope, let's say that I find a way to survive a sexless marriage... She plods along in her direction without a nod to what i want or need. Or vacation to Florida was CONSUMED with her agenda. Every morning she wanted to sleep in, drink coffee by the pool and take her time getting ready. Then she wanted hours on the beach and to watch the sun go down over the ocean. Then she had a list of restaurants she wanted to go to. Add that up. What's left for me? That takes us from waking to around 9pm. 

No matter what we talk about, she forgets within a week or two. No coping mechanism we try lasts long enough for me to recover. 

About 5 years ago we started swinging. It was foolish and caused a lot of damage. But I have to say that as dysfunctional as it was, it was wonderful having sexual partners who could retain my preferences and not be combative. 

What I learned from that was that I really am a one woman man, but I need someone who is actually there. I so deeply miss having connected sex. Sex with my ADD wife is like sex with a robot. She can't even make adjustments over a period of 26 years...

Any help... anything that would get me through this would be appreciated. 

One last thing... understanding is a pointless function for me. I mentally understand it's not personal. I don't care if it's intentional or not. I need some mechanism to make it stop - at least enough to find a drop of happiness.