This.You made it correctly, it seems! You might try another vermouth and/or whiskey. I like Carpano Antica and Dolin Sweet Vermouth. The Manhattan might not be for you, but you can check it off the list!
Watching hurricane coverage tonight with a Flower City/Noilly Prat/lemon zest Martini. Feel for the folks in S Texas and NE Mexico. No fun.
IMHO, give it a shot with with Bulleit Rye, Carpano Antica, bitters and Luxardo cherries. I might also recommend skipping the 45 seconds of stirring with ice and pour it over a large ice cube instead. The manhattan does not need to be ice cold, like FL Shaver’s martini would be .
Either way, happy sipping and stay safe