I'm 21F. I still stutter. Considering you're in high school, you should ask a guidance counselor about having a speech therapist come to your school (or if you're doing online learning, meet with you virtually) to help you. I did that in high school. Your stutter will never go away, but you're not hopeless. Speech therapy can help you gain more control over your speech and increase your fluency. You should definitely give it a shot!