First off, congrats on starting the masters! As for situations I think the context doesn't really matter aside from the fact that anxiety will rise and that drastically inhibits your speech. Try to talk slow, not matrix slow but slow enough you give each word time to properly come out. Don't be afraid of blocks if they happen they happen oh well no one's perfect but give this a chance I'd you haven't already. Believe you can do it and work hard at it since your gonna be speaking for the rest of your life.