Is it normal to feel attacked and attack when argue on the internet?

There's a couple things at play here when you talk to people online.

Ultimately, there's a difference between feeling attacked and being attacked. Both are common in online discussions.

Why do people attack people?

The anonymity and distance of the internet makes it easier for people to share strong opinions - for better or worse. There's a certain amount of psychology around the design of social media that pushes people towards confrontation.

Sometimes aggression is the default state for people. Depending on your world view that might be either sad or necessary.

That said, I believe there's a difference between a justified attack and an unjustified one. If someone is spreading hate, we all owe it to the community to fuck that person up with our words. If someone shares a harmless opinion then there isn't much call for a personal attack.

Why do I feel attacked?

If you feel attacked on the internet, there's ultimately two possibilities: you're being attacked or you're mistaken. For the sake of this section, let's say you're mistaken.

Non-verbal communication is an essential part of communication between humans, and is something that's hard to replicate in text. Ultimately, our non-verbal cues set an expected tone.

Sometimes when writing we recognize this and use a tonal indicator to set expectations. Emoji 🙄, gestures *rolls eyes* and, appending flags /s are all ways that we might set tone. These three examples all indicate "sarcasm" which for many people seems to be the default way to express themselves.

Sarcasm in particular is problematic because it often inverts the meaning of what was said. The phrase, "oh yeah, brilliant idea" has opposite interpretations if you're being sarcastic. Sometimes the writer assumes the reader will know what they intended because they were feeling sarcastic when they typed it. Of course, as a reader we have no way of knowing what the writer's feelings were at the time of writing.

Another element at play here is that a good deal of conversation on the internet is debate. Some people equate disagreement with condemnation, so if your feelings are hurt by that it's common to lash out. Many debates on the internet start civilly enough and then deteriorate to name calling and cursing in short order. It's wise to try to be the bigger person and assume no malice, because once it gets out it's hard to put back.

Statistics and Bias

You probably had the right idea that only about 1% of users are active commenters. Similar to that, there's also a phenomenon where the most vocal (and often inflammatory) users represent a similarly small portion of the group.

Our brains are evolved for survival, so they pay special attention to negative stimuli. Basically, they're always looking for trouble, and if you're looking for trouble you're likely to find it.

What this ultimately means is that we remember the bad things far more memorably than the good things. It also means that even if a small percentage of people are attacking others, because they dominate the conversation we start to believe that everyone carries that opinion. But as you point out, 99% of users aren't even commenting, so we really don't have a good grasp on what the larger population is like.

It also means that if you exercise your block list, you don't have to put in too much work to remove the most hateful people from your feed.

Closing

Anyway, I think you have the right idea. It sounds like you don't go looking for fights.

I try to keep a similar philosophy. If I disagree with someone then I'll seek to empathize or educate. However, if someone is vocal about my erasure or directing hate and violence towards people then I'll let them have it. I figure those people are looking for trouble and by golly I'll give it to them - it's always morally correct to punch a nazi.