First, understand that you are not alone. This is what brought many of us here (and some others that came here are/were the LD spouse) so we know the pain you are feeling.
That being said, can you give us some more background? Specifically, do you have kids? You said that your SL has never been great, does that count before your marriage? Has anything changed in your marriage or lives (such as other stressors like loss of a job, weight gain, etc.)? Any other information you could provide would be great.
Also, does she believe it is a problem in your relationship or is she just going along with the discussions because you want her to?
CB
Me; 42, W; 43 M; 16 yrs S12, D9
3/13 - "I want to move to XYZ City (four hours away) and it might be without you, not sure" 5/13 - "Not sure I meant that"