I do think it is possible that you have vaginismus, but would need to do an exam to confirm. The burning sensation accompanied by penetration can be related to the vaginal muscles being extremely tight. I think that when you are extremely aroused, you are releasing the tension in the vagina, which makes penetration possible and not painful. I would encourage you to seek out a pelvic floor physical therapist, or get a good set of dilators to start using. You can also give our center a call to discuss treatment options, or come in for an evaluation if you are in the area. http://www.mazewomenshealth.com