Man. I feel ya. That's really tough and I've absolutely been there. My first few semesters of University were awful. I stood up to give a presentation and just blacked out like you. Couldn't even get past the first slide and had to apologize and sit down in agony watching everyone else kill their presentations where I sat there dejected and embarrassed for the remaining 2 hours of class. With that said, those embarrassing moments are what can build you, and push you to be better. You were brave to even get up in front of the class when you were that nervous. Pushing yourself into difficult situations makes you stronger in the long run and can only help to build your confidence if you don't let a little misstep take you away from your ultimate goal. I really think you need to try both speech therapy (if you haven't already) and see a regular therapist. These two things have helped me immensely get out of my own head. You need to let people into your life. Share how you're feeling with others and let other people help you. That's what really helped me the most. Years of going to speech classes and a learning fluency techniques helped, but it was the mental barrier that needed to be broken down before I saw any tangible benefits. Good luck man! We're all rooting for you!