You're not stupid. You're expressing your fears.Lots of much bigger people here riding and loving it.
1st, I’m paranoid that people are watching me because to see a Clyde on a bike is not the norm here, at least I have never seen it.
Be glad they actually quit texting long enough to see you.
2nd, I’m not a fast rider, in fact I am anything but. I just like to take my time while others go at the speed of sound. And that makes me more paranoid because I keep thinking people are laughing at me going slower than them because I’m a Clyde.
I'm slow too. I'm not riding to be fast.
3rd, I’m going through the learning process of getting the gears right for what I want to do. So when I come to an incline, I am sometimes not in the right gear and by the time I have figured it out its too late and I can’t pedal so have to get off. Another reason for being paranoid and looking a fool.
Choose a small hill and learn it. When you have it figured out choose another slightly steeper one.
4th, I’m not confident that a bike will hold up to my weight (310) and the last thing I want is to have to get off because of a broken something or other and have to push it home. More paranoia – Clyde pushing a bike because he broke it!!
What bike are you riding? What maintenance are you doing? I bought the Cheapest Giant (Sedona) and spend more time tinkering with it than riding it. I like tinkering with it. My Trek 7300 needs almost no mainenance. The Sedona is a Wally World type bike only available in the correct size for me. Get a Bike Book and learn to maintain your bike.