Hi,
Welcome to ehealthforum,
The absent periods could be due to pregnancy (if ovulation had returned and if you have been sexually active), ovarian suppression/failure, uterine adhesions, hormonal changes, menopausal onset etc. It is difficult to comment on the exact cause without examining you and going ahead with further evaluation. You should consider visiting your doctor/gynecologist for further evaluation and assistance. Treatment as indicated (based on examination and investigations results) would be started to help you get your periods and regulate them. Be in regular monitoring and follow-up with your treating doctor/gynecologist and report any new/abnormal symptoms immediately. Drink plenty of water. Take adequate rest. Maintain healthy diet and lifestyle.
Take care.