Hello,
I have gone through your query and understood the concern. At the outset, let me say that you are very young and hence tend to have less well developed parts than the grown up. This can cause difficulty in sexual intercourse along with lack of proper knowledge. Sometimes, the hymen may be stiff and hence make penetration difficult. The tenderness in the vagina, the bleeding and the pain in the stomach that you are experiencing are the result of trauma to the soft parts. I would suggest waiting for some more time, allow tissue healing and get proper clinical evaluation by a specialist to detect the exact cause. Hope this helps.