Your symptoms sound most consistent with posture- and prolonged sitting-related mechanical back/neck pain. Sitting for 7 hours on a hard bench can definitely aggravate it. Anterior pelvic tilt or forward-head posture by itself is not necessarily a disease, and the goal is not to maintain a “perfect posture” all day — changing position frequently is more important. During class, try to change your sitting position every 20–30 minutes. If allowed, use a small lumbar roll/folded towel behind your lower back and a thin seat cushion. Keep both feet supported and avoid bending forward over your notes for long periods. During breaks, stand/walk for 2–3 minutes. At home, include 15–20 minutes daily of core strengthening, glute strengthening, hip-flexor stretching and upper-back/scapular exercises. Regular walking is also helpful. Avoid prolonged bed rest.

Consult orthopedic doctor