Hello, You have difficulty in inserting tampons and experience pain. You cannot have sexual intercourse because even after foreplay, use of lubes and trying different positions penetrative sex is not possible though you were relaxed. You have not mentioned your age, you should mention your age. You may be suffering from vaginismus and hence automatic tightening of the vaginal muscles occur due to fear of pain obstructing the penis to go in. You are suggested to do pelvic floor exercises, take the help of a physiotherapist for exercises. Resolve emotional factors and fear of pain. Get clinically examined by a gynecologist, to rule out any vaginal anomaly like vaginal agenesis/atresia, this will require minor stretching of the vaginal tissue with vaginal dilators. Do not try it yourself, it is done by a gynecologist. Anomalies like transverse vaginal septum or longitudinal vaginal septum that may require removal of fibrous tissue blocking the vagina. It will require surgical procedure. Get assessed by a gynae & treated at the earliest. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician