vivek.
All things panic are imagined or exaggerated. You know this from how you feel and what you think during a presentation.
Exposure will work but since you probably can't do enough presentations to small groups working your way up here is an exposure you can do. The object of this exposure and lesson is to get it into your mind that all these things are imagined.
You need a large mirror and some friends, hopefully you have both because you need both. Family will do but friends are better barring these a spouse will do. Peers or better is necessary. They have to be someone you respect or trust.
The object of this is to prove your fears are false and laughable. The basis behind all fears.
Okay here is the exercise. Stand where you can see yourself in the mirror and give a presentation. You have to be able to see your friends also. Their job is to interrupt you and do all the things you are imagining. Your job is to look in the mirror and prove them wrong. Their job is also to distract you so you can learn to stay focused. They do this by chewing gum and some nasty habits. You can choose which you can handle. Worried about how you look? Have them point it out. Look in the mirror. Not true is it.
If you aren't either crying or laughing it isn't working. At some point you should get angry if you are really serious. All of this is to get it in your memory that you are fine and these faults are false.
Truly good speakers believe in themselves, great ones don't care what they look like and all of then have one thing in common. They get angry when challenged and use the anger to find the answers rather than fall apart.
Another thing. Look at the floor when looking for answers it won't distract you.
You don't fall apart among friends, why should anyone else be any different.
If this doesn't work, there is always Propranolol. It is for stage fright but prescription only.
Davit.
Anyone want to add to this?