We need far more information.
If your boyfriend simply shoved a few people around during a scuffle, resulting in 8 very low-level 'common assault' charges, he'd probably just get a community sentence. Whereas a single offence of 'GBH with intent', at the very top of the scale, could result in life imprisonment. So we need to know far more information about what happened and, in particular, the exact charges that he's facing. (Common assault? ABH? GBH? GBH with intent?). Further, if any of his victims were police officers, children or 'vulnerable' adults, or if his offences were racially aggravated, the court will take a far more serious view of things.
You've also not what told us what the 'criminal' charges you refer to are (although, of course, assault charges are also 'criminal' anyway). Breaking someone's glasses is far less serious than knocking their house down with a JCB. Nicking a Mars bar is far less serious than defrauding someone out of millions of pounds. So what is he actually charged with?
If you seek to withdraw a statement in a 'domestic violence' case, it's the policy of the CPS to use that statement in court anyway, possibly resulting in you being required to give evidence in court to explain why you've changed your account of things. You also risk being charged with either:
a) wasting police time (if the police believe that your original statement was a lie) ; or
b) attempting to pervert the course of justice (if they believe that your original statement was true). If you were convicted of that offence you'd almost certainly be sent to prison.(There have been several high-profile cases where rape victims have been sent to prison for refusing to testify against offenders, so seeking to withdraw a statement is always to be regarded as extremely risky).