Get up, put on your pants and take her over your knee, pull down her panties and spank her. She needs to know you are the boss. It sounds to me she just needs to be reminded who is in charge. After you spank her tell her to get to her knees and suck your ****. Good luck!
Have you tried? Truly??
BAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA, I only read the question
I bet you can find out why she is cold if you ask her and tell her how important this is to you. If not she needs to go to the DR maybe hormones. You are a good husband right?
Divorce (you always can remarry)