What a coincidence, I am the exact same age and have the exact same problem :D My speech therapist gave me some tips: try to find a rythm in your speaking, like in a song or in a poem. As in, take pauses between words to slow down your speech. You can practice that by reading a text out loud Also let out some air when you feel like youre gonna stutter, for example, say "steh" instead of "st", sounds a little stupid but still better than nothing And try not to think about it too much, that's actually helped me the most.