Anxiety about transitioning into adulthood

Anxiety about transitioning into adulthood Its just a vent , these are the feelings i ve been having for a long time Okay so my teenagers are almost over . Im 19 now and im terrified of being an adult, and all those adult things , such as jobs , socializing , relationships , marriage , raising kids , career , university etc. i just cant picture myself being a succesful adult , satisfied with life and severity of my stammer together. I wanna do so much more with life and i just always find myself withdrawing and holding back from things. I was so introverted in high school and a built a protective wall around me. I just couldnt get out of my comfort zones during those 4 years, that i feel like i missed a lot of things , i thought i could do before i entered high school. Before high school was also pretty bad , but i didnt feel it that much because i was a kid and i didnt stammer much, i had friends , social life , did well in class participation and oral exams. But everything changed after i entered highschool. I just dont want university to be the same. I just wanna get out of shell , and do more with life. I just cant deal with having to hold back anymore or at least my career choice(medicine) wont allow me to. I have reached a point where im just done with stammering but still anxiety related to my stammer is just so much that i cant do anything i wish i did. I need some advice here.