I feel you mate, i am sorry that you have to go through all of this, i am sure that you are very skillful and social person, unfortunately, i don't have any advises, cause, speech therapist told me to speak slowly and breath deeply, yeah, as always, i have it from childhood too, when i was like you(3 years old), i couldn't speak at all, not even a single word, tho i was understanding everything, mom got worried, and she gave me some pills to fix it, it "helped" cause after that i start immediately speak sentences, but, here we are now, depression, sadness, sorrow, no desire to do anything, even simple things like eating or waking up, i really don't know what to do, speech therapist also told me that it will pass with age, but i guess she said to relief my stress and worries, I don't wanna sound pessimistic, but, i gave up, it's just so frustrating when you try something new to cure it, you waste money, and it doesn't work