Ouch, that sounds painful. Sorry to hear about the pain. Based on your symptoms, the cause is likely due to a muscle strain or pull in the adductor muscles of your thigh ( groin muscles). This is a common injury when you have a fall in the position in which you have fallen. Your best bet at this point is to stretch the area regulalry, holding each strecth for 15-30 seconds and performing this as much as possible during your waking hours. I would also suggest using a Over the counter anti-inflammatory such as aleve or ibuprofen. In the next few days you should use more regulalry and then you can gradually stop using these. If the pain persists for longer than a week, I suggest you go to your primary care and have a full evaluation to rule out things such as a hernia, hip fracture, or hip labaral injury. I hope this helps and i hope you feel better soon.