You probably wiped too hard I'm extremely obsessive about wiping and sometimes I can over due it and get a spot of blood and it'll start to sting a little a long while after maybe try using wipes it helps so the skin doesn't get as irritated with all that dry paper
Get some witch hazel, it is available at the chemist or drugstore and is very soothing to hemorrhoids. They are nothing to be ashamed of. You put some on a cotton ball and set it on the hemorrhoid. If it does not begin to heal after sitzbaths and witch hazel, ask your mother to set up a doctor appointment for you. She doesn't need to know the problem, if you're too embarrassed to say you have an anal issue, tell her you thing it is a UTI.
It sounds like you have a hemorrhoid. You are young to have this problem, but it runs in some families. Do you have trouble with dry stools or trouble passing stool? You may need to take magnesium citrate. Only mag citrate is right for constipation. It can be harder to find and I find it usually only at one drug store near me or I can order it on Amazon. I take 750 mg.
The itching is hard to take - it can be very distracting. You can do a sitz bath. Basically soak your bum in a tub of warm water for 10 or 15 minutes. It really helps.