Academic anxiety in demanding STEM courses creates a cascade of physiological stress responses that can derail promising careers before they begin. When students perceive introductory physics as psychologically threatening, their cognitive resources become hijacked by fear-based thinking rather than focused on learning complex concepts. This research demonstrates that targeted mindfulness interventions can interrupt this destructive cycle at its source. The study implemented structured mindfulness training protocols with college physics students, measuring both psychological markers of academic threat and objective engagement metrics. Results showed significant reductions in perceived threat levels alongside measurable increases in classroom participation and problem-solving persistence. Students who received mindfulness training displayed enhanced emotional regulation during high-stakes assessments and improved capacity to maintain focus during challenging coursework. The intervention appeared to create a buffer against the intimidation factor that drives many capable students away from STEM fields. This finding aligns with growing evidence that contemplative practices can rewire neural pathways associated with stress reactivity and executive function. However, the study's scope was limited to a single academic context, and longer-term retention effects remain unclear. The practical implications are substantial for universities grappling with STEM attrition rates, particularly among underrepresented groups who may face additional layers of academic threat. Rather than simply identifying struggling students after the fact, institutions could proactively equip learners with resilience tools. The research suggests that addressing the psychological dimension of learning may be as crucial as mastering technical content itself for sustained success in demanding disciplines.