(For a 45 year old man, I am in pretty darn good shape and yes, I am decent looking.)
Doesn't come across very convincing to me. A convincing statement to me would be...Yes, I am an attractive man.
Not, I'm attractive for a 45 year old man...and "I'm decent"? Those don't come across as very confident? Do you not realize that we women don't think...dang, he's good looking for 45...or at least I don't, and I know my close friends don't. Take my H for example....he's a very handsome man, although I know he has low self-esteem issues. When I first met him I didn't think...hey! He's good looking for 40-something, I just thought...that's a good looking guy!
Perhaps your self-image is something you could concentrate on.