It's not that you refuse or are bitter. It's the opposite of that.
You're happy in your new healthy relationship but you simply can't fall in love. Many months can pass by or even a year and nope, you don't ever develop infatuation for them. Your brain simply not produce those hormones to fall in love anymore. You lost the ability to ever be infatutated. They can be the greatest person ever but you just can't ever fall in love again.
You fell in love once and it was the biggest deception in your life. The person was literally cruel and sadistic (someone that really lacks empathy); a lot more than just a player.