<human>: Can you give me the gist of the text in a nutshell?

We met each other about 6 years ago. Long distance relationship at first but eventually we moved in together. Emotionally we are at a great spot. She knows and understands me more than my family and I know her better than she knows herself. It's wonderful.

The problem is that as we became closer emotionally, our sexual situation has become nonexistant. First 2 or 3 years were pretty active, but now not even once a month. Why is that? I'm not sure. A few years ago she found out her thyroid level was slightly lower than normal. But she hasn't done anything about it. Possibly because she doesn't like the idea of having to take something on a daily basis, for something that is only slightly low. For me, over the last 18 months, I feel my desire for sex to be increasing. But it's hard to get into it, knowing (and seeing) she just doesn't have gusto, or desire for it.

Over the last few months, I've brought up wanting to have sex more. She's said she enjoys it when we do, but just doesn't have the desire for it often. I've brought up the idea of some type of open relationship, and she is very against that.

What do I do? I feel foolish to break up with her over sex, because everything else is really great. On the other hand, I think eventually this situation may breed resentment. This [comment] in DeadBedroom does not give me hope. 

As a side note, I just discovered /r/DeadBedrooms/ just a few moments ago. It seems I'm not alone in my situation. That is both comforting and depressing.
<bot>: Great relationship, but no sex. Do I break up because of it, or just deal with it because everything else in the relationship is great?