For The Last Two Months I've Had A Sweaty, Spotty

For the last two months I've had a sweaty, spotty and embarrassingly smelly bottom that's never happened before. My diet hasn't changed in any significant way; maybe a little more caffeine but no more than normal in a year. The last week I feel clammy all over, and there's a hint of fishy smell. I'm a 45 year old healthy and hygienic man. It's all very embarrassing though no one has mentioned it at work. I describe the smell as a miasma, as that how it seems. Thanks.