I am very sorry to say, but the decision to press charges or not, is not and has never been yours to make, this is a very common error many people make because often they see it on TV etc.
In reality, you are the victim and a prosecution witness.
You made a complaint of domestic abuse to the police, they would have investigated the case possibly arrested the suspect. The case must haver been thought serious enough to charge him to court by the Crown prosecution service. It is they that decide whether to charge or not.
It must also be serious for him to have been remanded in custody pending a trail, either that, or he ignored bail conditions and breached them leading to his re arrest and remand in custody.
You can, make a new statement to the police stating that you do not support a prosecution and that it has all been blown at of proportion, that statement will be taken from you and passed to the CPS to review. Even if they decide to ignore that and continue to trial, the statement will be given to the defence, who can introduce it as evidence in court to support their case for the defence.
You are certainly likely to be summons to court as a prosecution witness. If you start to say that in court, the prosecution are likely to ask the court for permission to treat you as a hostile witness so that they can question you differently.