It appears you are in a serious condition. You must talk to your parents in a very frank manner. your parents will understand and will try to help you. Teenagers do some mistakes. they are not taken sriously, but they will take your health serioudly and help you out. Do not wait for any other help. Just tell your parents/ guardians.
Sounds like you have severe constipation and have been struggling to empty your bowels.
You need to eat more fibre rich foods, like fresh fruit and vegetables and drink more water. Cut out the sugary foods and drinks, the processed foods and the junk foods.
Tell your parents to book you an appointment to see the doctor.
The doctor will probably examine you so make sure you wash before you go and wear a clean pair of pants.
You may have haemorrhoids, or a fissure (a tear inside the colon).
The doctor will probably prescribe a stool softening medication and some creams or suppositories to help when you empty your bowels.
Get an appointment to see the doctor.