Mom of a 5 year old son that stutters.

Mom of a 5 year old son that stutters. Just looking for some hopeful info. When my son first started having a stutter he was in pre-k and most of the kids in his class didn’t really notice anything. I knew as he got older that the kids would eventually start to make fun of him. Today was the day I have been dreading, he said his friends at school were teasing him about his speech. He’s been in speech therapy for almost a year now, he has learned strategies to help but he doesn’t apply them. I’m not sure if it’s just his immaturity or what, but I don’t want this to affect his self esteem, he’s already a sensitive kid. Has anyone had a similar experience? How did it turn out?