You can close your eyes, stick your head in the sand, try to explain it, justify it but one thing is for certain, unless you change your attitude about it, NOTHING will change. You both will continue on the same path until the relationship becomes polarized and then it will be over. Is that what you want? I believe you will continue to feel resentment and bitterness unless the tide turns. It's already on shakey grounds, wouldn't you agree? But keep going on the path you are on and it will crumble. Who is going to turn the tide?
You have some tough decisions ahead of you. Do you love her and want the relationship to continue or are you looking for a way out? Your previous comment about preparing yourself for your "next wife" suggests that you are not fully committed to working on the issues. It's all or nothing, it's impossible to claim that you are working to save the relationship if you are already thinking about a "next wife." Decide if you are working to save the marriage because you value it or if it is no longer worth saving to you and then follow accordingly. Furthermore, should you find a "next wife", what makes you think that these same issues will not emerge with another? It's not so simple. Sex drive is not static-many things in life influence desire, included but not limited to: stress, medications, age, hormones, and the overall health of the relationship. It's only PART of the relationship, not THE relationship and sort of a barometer of the state of the union. Sex problems are rarely just about sex. You can find someone with a drive similar to yours for a while but you won't have the basis for anything lasting.
Since you are the one that recognizes the severity of the problem, have you communicated the seriousness of it to her in a way that she understands? Have you suggested counseling/therapy to deal with the issues in your marriage?
Are you grateful for what you do have with her or just focusing on what is lacking? I do sympathize with you, I really do but try being a former hot tamale who is now divorced and behaving and not getting ANY. Believe me, once a month would look pretty darn good right now. Now divorced, theoretically speaking-I have all the opportunities to "play the field" but it's not the lifestyle that I choose to lead.
Statistics show that divorced people "get it" even less than married people. It's not all it's cracked up to be. Instead of looking for burning bushes here, take action-"fix" yourself first, and then concentrate on the relationship-communicate, therapy, whatever it takes to work through this difficult time.