Fictional Heartbreak

Today I am going to try my best to hurt someone I care for very much. Truly, it's going to hurt me more than it does them.
Now before you call 911 and have the constabulary at my doorstep, let me assure you that however real they may be to me, it's going to be entirely on paper.
But in the best interest of the plot, someone has to go down in a fairly dramatic fashion for my heroine to have the impetus to rush in and save the day. I had no idea when I began this book that I could become so attached to someone entirely in my head that it made me stutter-step in my writing. Actually, to be completely honest, the 'book' didn't start out as such-I sat down to write a short story to get the creative juices flowing so that i could start on a book later. It got so out of control, word-count wise, in the first few chapters that I threw up my metaphorical hands and gave myself over to it and rolled with it. Now I find myself thinking of my characters at all hours of the day and night, having revelations about them, learning things about their motivations, in essence falling in love with them, no matter how flawed they might be. So when i realized that one of them had to be hurt, it haunted me to the point of obsession. I kept trying to re-do the plot, adjusting the dynamic so that I could weasel out of it, but to drive home what I wanted, I couldn't find my way out of it. Thankfully, I don't have to do away with them completely. If I did, I would have to prepare a memorial service, be in mourning, wear black (oh wait, I already wear black most of the time), and mope around for days. But no, I just have to hurt them badly. Trust me though, someone's going to pay. That's the up side that will have me sitting down to write today. Plot driven pain is lamentable, but I can sure as heck make my bad guy pay in spades for it.