Im really sorry you're going through this. I felt the same way when I was younger. I've struggled with various speech deficiencies since I was 5 years old. Some days it's terrible, some days it seemed to disappear entirely, but the nagging fear and social anxiety never left, and it's crippling when you feel like you could be so much more. The only solution is to actively seek methods of improvement. I'm now 32, and through years of trial and error (never went to speech therapy. I was too humiliated even for that), I found things that worked for me and my speech. I still struggle with regular blocks on certain letters, but it's a willing exchange for the self-loathing that a heavy stammer gave me. You can do this. Find ways to minimize your issues, even if they seem strange at first.