OK, given that it was violence against you, you can be compelled to give evidence. A summons can be issued to get you to court. You can be arrested if necessary.
Many people get into the witness box and then lie or "forget". It is at this point the prosecutor will apply to treat them as hostile and put their previous statement to them. Given that you admit that it was true, I have no doubt that the Prosecutor will put you forwards as a witness of truth.
You may find this draconian, but this law exists to protect people who are genuinely in fear of violence and may feel intimidated into not giving evidence.