Surgical emergencies often trigger acute cognitive overload in novice physicians, impairing their decision-making under pressure. Although Virtual Reality–based Stress Inoculation Training (VR-SIT) shows promise, current systems fall short in delivering real-time, effective support during moments of peak stress. To bridge this gap, we first conducted a formative study (N=12) to uncover the core needs of novice physicians for immediate assistance under acute stress and identified three key intervention strategies: self-regulation aids, procedure guidance, and emotional/sensory support. Building on these insights, we designed and implemented a novel VR-SIT system that incorporates a just-in-time adaptive intervention framework, dynamically tailoring support to learners’ cognitive and emotional states. We then validated these strategies in a user study (N=26). Our findings provide empirical evidence and design implications for next-generation VR medical training systems, supporting physicians in sustaining cognitive clarity and accurate decision-making in critical situations.