As a participant in a trial, your rights come with certain duties. You are not obliged to use all your rights as a victim, but if you do, you should comply with your duties as well.
You don’t have an obligation to use all your rights in criminal proceedings. For example, you may decide not to ask for compensation for the harm done to you as a civil plaintiff. Or, you may choose not to be present at the trial, in which case the criminal proceedings could continue without you.
However, if you choose to actively take part in the trial, you must comply with your duties in it.