That's what happened after violently fisting my asshole. How am I supposed to tell my parents that I need to see the doctor because I've damaged my rectum?!
Your hand doesn't look like it was fisting something. You're full of shit unless you can prove otherwise with a timestamp.
Don't worry just take a bath (with cold water if you can) like 20 minutes or so. After this, wear a clean underwear, with a little amount of hygienic paper in them to dry the rest of the blood (if there still any), go to bed and sleep a bit, don't eat very much for a couple of days this way you don't need to go to the toilet, if you're going to eat, eat vegetables, water, and orange juice only.