The internet is a public place

…or, at least, you should treat it as such. When moving through public spaces you observe common decency, you don't play music on a speaker, you make sure your cock isn't flapping in the breeze, and you don't take up immense amounts of space. The same applies online. You should understand that there are many other folks out and about on the 'net and you should respect their use of the space, and with any luck they'll respect yours.

What does this imply?

You should follow netiquette when online. A few things to avoid

Public means public

You should assume that what you post is both public, and could be tied back to your real identity. It's trivial to archive an entire discord server or Twitter DMs. It's generally not difficult to find the real identities of internet users, even those who use pseudonyms. Assume everything you post is going to be online forever. Once you hit post you have no way of controlling what others will do with that content.

1)
making one post followed by another before anyone can reply. You should edit the original post instead of double posting
2)
I get that you're lonely and sad, but public forums/chatrooms are not the place for it. Go talk to a friend or find a support group online. Strangers online don't want to read about you being sad
3)
posting the same thing in multiple areas, just link to the original
4)
move your personal chats or a conversation that spiraled off topic else where. It helps spread out conversation, if everyone posts in one or two channels it becomes hard to follow. It also pushes your conversation into the feeds of people who are not interested
5)
Compress your media, avoid hotlinking media, etc. Bandwidth costs people money, respect that
6)
it makes conversations easier to follow, just quote the line or three you're replying to