Hello,
Extremely painful periods with light pink discharge may be part of underlying inflammation as 
adenomyosis, 
endometriosis or other clinical condition. Primary work up with per speculum examination via expert 
OBGYN, necessary reports of cervical swab, ultrasound of the abdomen & pelvis are of paramount importance to proceed for the query evaluation and further guidelines.
Till that time, following advise would help you:
- Abstinence from sex till recovery
- Vaginal hygiene care
- Plenty of liquids to prevent secondary bacterial infection
- Antispasmodic medicine as 
dicyclomine or 
drotaverine prescription
- Avoid prolong use of same tampon
- Avoid stress and anxiety
Hope I have answered your query. Let me know if I can assist you further.
Regards,
Dr. Bhagyesh V. Patel, General Surgeon