Get clinically examined by dentist.

Hello. Please use a soft bristle toothbrush and follow the correct brushing technique. Avoid over brushing, brushing for too long, and hard brushing. Hard brushing can cause trauma to your teeth and gums and also cause periodontal problems.

First of all, you need to understand that your mouth and teeth are very delicate at your age and you should not brush forcefully... U can search about Appropriate Brushing Techniques.... Lack of knowledge about gum and teeth care resulting in devastating problems so you should visit dentist and get to know about oral care thank you.

Proper brushing technique advised.If more mobility get checkup