"It Seems I've Fallen to Another World and Started Over as a Child"

I am a 16-year-old high school student. During a basketball practice match, I was suddenly transported to another world. For some reason, I have the appearance of a 3-year-old, but... I can't remember my name. I have other memories, but it seems my mental age easily reverts to that of a child, and my emotions are unstable. For now, I've found a place to live and a guardian, so I'll rest and think about what to do going forward. A story about the protagonist who was transported to another world, using cheat abilities and chantless magic to survive.