How to get over a fear of crowds when i am the speaker?

Practice a lot: Public speaking is difficult if you are shy, or unsure of the topic or material that is being presented. Practice in front of a mirror, or a familiar person first, carry notes in case you "get stuck", and pick one person out of your audience to address with eye contact which will "eliminate the crowd" and ease the anxiety..

CBT: Seek a cognitive-behavioral therapist who specializes in phobias. One method they use is systematic desensitization which slowly and incrementally brings the person closer and closer to the thing they are afraid of in slow, graduated steps that help make the anxiety more tolerable.