I Am 67. Lost My Sex Drive When I Aged

I am 67. Lost my sex drive when I aged and that hurt my relationship with my partner of 30 years. I started testosterone lotion prescribed by my doctor. I had amazingly good result for about a year but had to keep increasing the amount. I am taking as much now as my doctor will re commend. I am no longer getting desired effects. I feel like I have sort of become resistant to it. I am considering stopping it and hoping that if I get it out of my system that I could start it again later and hopefully have my sexual arousal enhanced like when I first started taking it. Do you believe this would possibly work? How long would I have to be off of it to get it out of my system? I realize this won't work forever but we would really benefit from a little while longer