Can´t find a movie I saw years ago, LOVED it but cant remember the title or any of the actors in it

Basically the movie was about this big kid, that started being best friends with this other small kid, who happened to be his neighbor. The small kid was really really smart and was also giving classes to the big kid. The small kid had multiple sclerosis (i think) and a hunchback, used canes. The poster of the movie is from a scene where the big kid puts the small kid on his shoulders to see fireworks.
SPOILER alert, the ending scene is sad af. Basically an ambulance picks up the small kid and he dies. The big kid goes running towards the ambulance in hopes to find his friend but gets lost. He gets depressed and doesnt even go to his friends funeral. Thats all I can recall. Been looking for this movie since I saw it in class, like 7 years ago or smt. I would really appreciate it! Thanks you for the help.

The Mighty?