Seems the problem here isnt actually your stuttering, its good old social anxiety. And the only thing that really helps there is exposure. I know its hard, but try to not focus on yourself while in a conversation. Your mind should be on what they are saying, try to respond on their words with your own experiences and stuff. If you are getting to stressed then you cant focus. Take a minute to yourself (bathroom or something) and breath in and out on a 10 sec basis, in 10 sec out 10 sec repeat. Sound like some fucking new-age bullshit but this really works wonders. Remember that the problem is within yourself and the only thing that can help it is yourself. The stress and "awkwardness" your feeling is your interpretation of what is going on. Try to in retrospect look at the situation objectivly, was it really that bad? Did i really fuck up? If someone did that to me, how would i react? If nothing works then just remember that it gets better with time. Pretty much everyone in here had social problems when they were around 16-18 years old, but the older you get the less fuck you give. It gets better, and only you can make it better, we belive in you mate.