There are not many youth dramas with this trope that come to my mind but i think in Master of Study has a character that struggled similarly. I didnt finish the drama so idk if it is worth of recommending.
Page Turner has a disabled female lead who is struggling and a friend helps her. But they dont start the story as friends.
For some youth dramas with supportive friends who love each other I rec Age of Youth. Its about 5 university students who live together. They go through different hardships and help each other. One of them is in a terrible relationship which escalates into kidnapping/abuse and others save her.
And finally I rec a movie Sunny. It is a really beautiful movie about friendship.