My husband is in court 3 or more mornings a week doing Court Watch (volunteer program that follows those that have committed crimes in our neighborhood, or those that live in our neighborhood, through the court system).
I cannot tell you how many times the victims of domestic violence drop the charges (or just don't show up). And how many times the perpetrator is back, again, in court. There is one woman that the police, judges, etc. are just waiting to hear has been killed - she's filed 9 times against someone but continually drops the charges. The police have vowed to bring this guy in if he so much as spits on the sidewalk, just to give HER another day to live.
Please know that what you are doing is IMPORTANT to follow all the way through. You may be saving your S2BX. You definately are saving some other person in the future. And yourself and you family.
If you still have doubts, see if you can find a victim's advocate group to talk to you - some will even go to the court with you as "moral" support.
YOU are a STRONG person, and you are doing what is right to do.