Do you have a gay community nearby? It sounds like you're in a rural area but do you have a friend in a bigger city you can visit and visit some bathhouses & bars? Maybe try the "lifestyle" on for size?

Coming out at any age is difficult but when you add a wife into the equation, it's going to be tough. Then again, deep down, perhaps she senses something is wrong and won't be as surprised as you think?

No easy answers.