hi thanks for your query.let me tell you that you seem to have injured your urethra most likely.violent sexual activity is most likely to result in genital tract injuries....to assess your degree of injury you need to observe if the blood in urine is at the beginning or at the of end of micturition. this could give possible clues about level of injury either at urethra or bladder respectively.these injuries are more prone to develop urinary tract infections.i suggest you drink 3 to 4 liters of water and crane berry juice to prevent infection.use tab norfloxacin 400mg bid for 3 days.do not engage in sexual activity until the leison heals/bleeding or pain stops.always practice safe sex .thank you.