The CPS has a policy of proceeding with domestic violence prosecutions with or without the alleged victim’s co-operation as far as possible. In the past enormous amounts of police, CPS and court time was wasted on prosecutions where the victim had withdrawn their co-operation. There was also a widespread belief (probably with good basis) that many victims were being intimidated into retracting their evidence.
That’s the background, now for the practicalities. Having made an initial statement making the allegations this cannot be withdrawn. It is in the hands of the police and the CPS and remains so. What you term your “withdrawal” statement is simply an addition to the information you have already provided. If your husband pleads not guilty and the matter goes to trial, unless he agrees to your evidence being read to the court (which is most unlikely) you will be asked to attend court. If you fail to do so the CPS may ask the court to issue a witness summons and this request will almost certainly be granted. Once you have been served with this summons you will be committing an offence if you do not attend. You may face arrest and if necessary will be brought to court on the appointed day.
Assuming you do eventually get to court, if you refuse to answer questions you may be declared a “hostile witness” and will be liable to cross-examination by the prosecution. You may be questioned as to why there is a substantial difference between your first and second statements.
All this gets very messy. You would be well advised to continue your co-operation with the CPS. You can ask, as the victim, to have your views made known to the court and it is far better to do this whilst you are co-operating with the prosecution.
Finally, the reason this is now CPS policy is that perpetrators of Domestic Violence rarely “get better”. In fact, statistics show that in a vast majority of cases they get worse if their actions remain unaddressed. Better to deal with it now.