SENSE & SENSITIVITY DEAR HARRIETTE: I feel like I am constantly making mistakes in love. I am 23 years old, and I have had a few bad relationships. They started out OK, but every single time, something weird happened. I feel like I stay too long or for the wrong reasons. I make smart decisions in other areas of my life, but in romance, I suck. My friends all say that I am a nice young woman, I hav…