Should I start a course on how to overcome stuttering in 21 days?

Should I start a course on how to overcome stuttering in 21 days? Hi everyone, I am 28 years old. I stuttered seriously for 26 years, but after joining a course, I am now fully confident, happy, and speak fluently. The course was in Hindi and included various practices and exercises such as: 1. Meditation 2. Yoga and deep breathing 3. Self-acceptance 4. Silent and loud laughter 5. Exercises to boost dopamine, oxytocin, serotonin, and endorphin levels 6. Advanced meditation to overcome overthinking, anxiety, and fear 7. And many more. These practices can be done anywhere, anytime. I believe that by following these practices, one can achieve inner happiness, and their fear, grief, anger, and tension will vanish. The course will be offered in three levels: 1. Free course 2. Intermediate ($300) 3. Advanced ($300) Is the pricing fair? Please let me know your opinion. Feel free to ask me anything about stuttering and how I overcame it.