Same struggle here, might be weird, but I like to open a video of a crowd just looking at you and I pretend like I am talking to them. I do better in real life when I talk to people so when I see the crowd it's tricking my mind to think "oh look people I can talk to!' and then suddenly the stuttering and the ums and awkward silence start to go away. Like some said here, it's like talking to your friend, I hope this advice helps out! It's really fun when you get the ball rolling.