I think meditation is hard to give advice on, I started with some guided meditations and then I took it from there. Why not give it a try and see what you can do. Being mindful and relaxed may help you in other ways as well. But if I were in your place and would give presentations I would use some relaxiation method when I get to a block. For me, relaxing with the tounge and breathing correctly usually does the trick for me. You can always study some rhetoric to give you the upper hand. It will give you more experience in doing presentations and with exercise I'm sure you will find ways to treat your stuttering. When someone seeks," said Siddhartha, "then it easily happens that his eyes see only the thing that he seeks, and he is able to find nothing, to take in nothing because he always thinks only about the thing he is seeking, because he has one goal, because he is obsessed with his goal. Seeking means: having a goal. But finding means: being free, being open, having no goal. You never know what will help you in life so be open for ideas. Hope you don't have anything against me quoting a bit.