I'm Afraid I'll Bring Down the Internet
The Internet was originally built to ensure that, in the event of a full-scale nuclear attack on the United States, the government and military would retain full communications. The Internet is, quite literally, a net surrounding the entire globe. No matter how big a hole you punch in it, there's still a zillion other ways for information to get from anywhere on the earth to anywhere else on the earth.
Using your computer, you cannot punch even the tiniest hole in the Internet. To bring the Internet down, you'd literally have to blow up the entire Earth. Nobody can do that with a computer, either intentionally or by accident. (Thank goodness, or we all would have been dead a long time ago).
Here's another way to look at it. At any given time there are about 30 million people online. A good 20 million of them have absolutely no idea what they're doing. If it were possible to bring down the Internet through sheer incompetence, the Internet would never work. But it always works, twenty-four hours a day, seven days a week, and has for over 20 years.
To summarize, you cannot harm the Internet in any way, shape, or form, no matter what you do. So you can write that fear off forever.