The police can apply for the criminal complaint even if you don't want to proceed. Given that victims in domestic violence situations often deny the abuse occurred, it will make difference to the charging process if you were to recant your story. You did allege at one point that he hit you, and that's enough probable cause for a criminal complaint to issue against him. Your boyfriend should get a lawyer immediately to protect his rights, and he should not make any statements to the police as anything he says may be used against him later. If you say you lied, you could be charged with making a false police report, but that does not mean that you have to cooperate with the prosecution in any way in the future. Once the police are involved, the alleged victim has little to no power to "drop the charges"; only the Commonwealth can choose to drop the charges, and many DA's office have a no dismiss policy when it comes to allegations of domestic violence. I'd be happy to discuss this matter with you or your boyfriend further at your convenience.
Bets of luck,
Dominic Pang (617-538-1127)
Unfortunately, you can not stop the process once you have started it. The police will arrest based on yourinitai representation that he hit you. The DA will try to prosecute him and may even threaten to file charges against you for filing a false police report if you try to recant what you originally stated. The best thing that you can do at this point is that your boyfriend needs to hire a good criminal defense attorney. There are ways to deal with this but none of them are easy or simple. A seasoned criminal defense lawyer will know how to navigate through it with the end goal being to get your boyfriend's charges against him dismissed and to avoid having you charged with either perjury or filing a false police report. You should hire an attorney who regularly practices in the court where your boyfriend is charged since a lot may depend upon his/her relationship with the ADA. Good luck.