It really does seem that way. She isn't doing or trying to improve the relationship. I have improved my behavior, compliments, asking to help, trying to woo her with breakfast in bed and taking the kids out, etc... I pay her compliments and show enthusiasm with her accomplishments. I tell her, come on babe let's have some fun while we can, we are both 40, I'm Type 1 diabetic and don't have ED, yet. I seriously wish my sex drive would just go way. I mean wtf?
Well, you've stepped up your game, which you needed to do to prove that it wasn't on you.
Now it's time to do the 180.
Have a conversation with her where you point out that, as she doesn't prioritize your needs, you will no longer prioritize hers.
Let her know that this will undoubtedly result in the end of your marriage at some point in the future. Let her know that, while you have no intention of looking to be involved with other women, you will certainly be more vulnerable if the situation should arise. Let her know that you will probably be looking to end the marriage when the kids are grown if not sooner. Only do things for her that you would do for anyone. Get a life that someone else might want to be a part of.
Stop initiating sex, consider refusing when she initiates on her terms (who wants a sex life that is completely controlled by the other person?).
Focus on yourself and being a father. Become a better person, someone who will have an easy time attracting quality women when the time comes.