Rhenny
Adventurer
Great advice so far. I'll just add a little.
It is really awesome to watch other DMs (Chris Perkins, Matt Merced, etc.) but it is just as important to forget them and be yourself. It sounds corny, but I've always found that when I try to be like someone else, I don't have the same confidence or enthusiasm that I have when I'm just being myself. The same goes for running pre-written adventures. Sometimes following a script zaps the energy from me, so I've learned to take what's written and make it my own. Don't fear cutting stuff, changing stuff or adding stuff. All this takes time and practice to develop so like others have said, don't be too hard on yourself.
Another observation that may help you feel at ease is understanding the different way players and DMs think about the same game. In my experience as both a DM and a player, I've found that DMs often feel as if a session was less challenging and exciting than the players. The DM knows so much more about each encounter and possible next steps. Players don't know as much about the adventure so they feel more of a sense of mystery/unknown. If you keep this in mind, you can often use the fear of the unknown to raise tension and make the game more exciting, but at the very least, knowing this should help you be less hard on yourself.
It is really awesome to watch other DMs (Chris Perkins, Matt Merced, etc.) but it is just as important to forget them and be yourself. It sounds corny, but I've always found that when I try to be like someone else, I don't have the same confidence or enthusiasm that I have when I'm just being myself. The same goes for running pre-written adventures. Sometimes following a script zaps the energy from me, so I've learned to take what's written and make it my own. Don't fear cutting stuff, changing stuff or adding stuff. All this takes time and practice to develop so like others have said, don't be too hard on yourself.
Another observation that may help you feel at ease is understanding the different way players and DMs think about the same game. In my experience as both a DM and a player, I've found that DMs often feel as if a session was less challenging and exciting than the players. The DM knows so much more about each encounter and possible next steps. Players don't know as much about the adventure so they feel more of a sense of mystery/unknown. If you keep this in mind, you can often use the fear of the unknown to raise tension and make the game more exciting, but at the very least, knowing this should help you be less hard on yourself.