What Causes Constant Wetness In Vagina?

I am 53 and post menopausal. A few years ago I experienced a lot of dryness in my vagina. I am now single and haven't had sex for 15 months. I have recently, since the new year, been doing more exercise, eating more fruit and vegetables and drinking more water. I now find that my vagina gets very wet. What could be the cause of this?