In my general opinion, as a teenager, sometimes there is compromised oral health due to consumption of fast foods which leads to deposition of plaque and calculus around the gums and make them weak. Thats why when you brush a bit harshly, bleeding occurs.
Exact diagnosis can only be told by video consultation once if you can share the pictures of your gums and teeth.
Next Steps
Kindly opt for video consultation once to get a proper diagnosis and treatment.
Health Tips
Avoid harsh tooth brushing, Use soft bristle tooth brush, consume
vitamin c for strong gums.