I was in similar situation multiple times till high school. However things improved in college because of two things - practice and a firm resolve to improve my speech. Don't care about others, just focus on yourself. Push yourself in front of others and speak. I know it sounds freaky. But beyond that is light. Also watch the video of Bill Wade (Bain senior partner) posted on NSA's channel. There are lots of things in that video that you can learn from. Basically you have to develop strong conviction that it will get better. And believe me it will. This is coming from someone in late twenties having gone through what you described multiple times.