Often I have found myself in a similar situation of becoming infatuated with a woman who seems to be in a bad relationship. Kinda like I want to be a big hero or something. As a matter of fact it is this sort of "rescuer" mindset that fires my romantic passions, it seems like it is hard for me to get excited over a single, well-adjusted female.
All of the girls I dated in high school had terrible fathers who either were no part of their life or abused them in some form. These are the girls who grow up to marry abusive men. Gotta stick with the familiar.
When I was in the troof I became very attracted to what seemed at first to be the most wonderful, sexy sister I had ever met. The attraction was felt by both. God I went out of my mind over her (literally, I almost checked in to a mental hospital over her). She had recently divorced a man that she was married to for many years. He was extremely verbally (and sometimes physically) abusive towards her. The more I got to know this sister however, the more I could see that she was just the type of woman who would slavishly submit to an abusive man. She had some very deep issues that needed dealing with. And she had the same sort of cheery, sociable attitude that you attibute to your coworker. She was the most intoxicatingly attractive woman I've ever known, but a real relationship between us would have been a complete disaster. By the way, her father was an old-guard JW, and never once spared the rod in raising his kids. I think this is where many of her issues may have stemmed from.
I don't mean to blame the victim, but women who are in these sort of relationships are often emotional powderkegs. Dude, get your mind off this lady real fast. Stop sexually fantasizing about her, that is what feeds the obsession.