New Job Blues

So here I am, a week into my first real job, and already feeling like a fraud. Today, I was supposed to send an email update to the whole team, but when it came time to write it, I completely froze up. My mind went blank, and instead of writing about our project progress, I ended up listing all the snacks in the kitchen pantry, every single brand and type of chip, cookie, and candy bar we had. And you know what’s worse? I accidentally hit 'send' before fixing my mistake! Now everyone thinks I’m either really lazy or clueless. Is this normal to feel so out of place and unsure about simple tasks like email updates? Any advice for getting through the first month without making more ridiculous mistakes?