I’m the exact same it’s only in stressful or nerving situations see if you’ve got this far in being a med student can do anything! All people say it’s confidence related and it’s not. Youve all the confidence for being a med student it’s neurological it’s not your fault! Do not stress about it because I bet if u didn’t do a presentation u can speak properly to people it’s only nerves but don’t let it affect you.