I bet you if she found you on here the first thing she would say was "what was I not enough for you??"
Anyway deadbedroom is real so go check out this support group
www.reddit.com/r/DeadBedrooms
I also found
www.amazon.co.uk/Married-Man-Life-Primer-2011/dp/1460981731
Pretty good, but hasn't worked for a while...
Best advice don't take it too personally (hard to do seeing that it's you that she no longer fucks) .. look after you, go to the gym, talk to other woman (as friends don't fuck them), and stop acting like a fucking beta, don't wash the dishes every night, take the kids away for the weekend without her, you may need to build a strong bond with them because the final bit of advice is if it does not come right after you try implementing some of the advice in the book and chat room on yourself then the problem is her and you deserve sexual happiness and spiritual fulfillment in your life and having someone at home continually rejecting you ain't going make that happen...
Ps also make sure she ain't fucking someone else cause you know that normally puts them off fucking you...
Good luck..