About concentrating on the music instead of the emotion: you definitely need the emotion. What's the point in singing without it?

But oh! what a wonderful feeling you have when you believe that you're singing as close as you want to musical "correctness".

If you can stand it, yes, do what Alice suggests, and take lessons from a professional. But keep in mind that you're trying to have fun. If the lessons dry up the expressiveness that you want, drop 'em. Musical "exercises" may be the fastest way to get good, but I loathe the idea of such "exercises" in something that feels fairly sacred to me. I'll keep getting better very slowly, thank you :-)

I think, far better than lessons, is a place to practice and make mistakes without embarrassment. You'd need that to benefit very much from the lessons anyway.