sexless marriage

I have been with my partner for 12 years now. I know the initial passion fades in relationships, it is not my first kick at the can, I was married before this for 15 years, but I can’t remember the last time we have had sex. It seems neither one of us wants to make the effort. I wonder if I have a hormone imbalance or if aging has just turned me off of sex period. I don’t feel this is normal and I want to feel sexy again, and I want to have sex with my partner. I have heard the coaches say it is all just thoughts that create these actions, but I have no idea where to start. I can’t just conjure up some idea in my head that I am sexy and I want to have sex. Please help!