I have gone through/am still going through similar experiences, and they've been reflected in my online writings and behaviors a ton as well. Often to my detriment. Especially in Discord servers, and "Private"/locked Twitter accounts when I still used them. The way I exhaled the suffering that I'd been experiencing outwards onto the web often negatively changed the way friends and strangers perceived me or interacted with me.
My theory as to why I did this is: humans are interesting creatures. We feel in chemicals, but we process and understand in language. Turning chemicals into language is how we process and express what we feel. In the pre-digital era, people would process their feelings linguistically by praying to gods, telling extremely close friends and family members, or writing in journals.
Then typewriters, and later, computers came along. Our words-per-minute were faster on those than writing words with pen or pencil by hand. Though the slowness of writing better enables us to process the weight of what we write, the speed of typing gets the yucky feelings out faster, leading to more rapid relief.
Even later, we got the Internet. Self-publishing on it used to be weird, costly, and technical, but the barriers to entry have diminished with webhosting services, paid and free, and social media/messaging platforms. It's easier than ever to connect one's thoughts to an audience.
When I was carelessly sharing expressions of my pain online, I felt faster access to a wider audience of people who could validate that pain. Unfortunately, that audience is full of a lot of people who have a lower-context understanding of who I am and what I've been through. So, without that context/understanding, they couldn't properly validate my pain even if they wanted to. Additionally, a lot of them are simply scrolling to get a quick laugh, or, even thoroughly entertain themselves, but not to understand or validate my pain. Thinking back on it, I'm not sure I'd even want them to.
What fixed the cycle for me was returning to journaling. I used to journal in grade-school, but stopped once a family member read through my physical journals, and Tumblr blogging took off (a side-account on there became my public, anonymous journal of sorts). I began my re-entry into journaling with
Obsidian. It easily lets you make a vault of daily note templates that can be used for journaling, among other things. Syncing it to my phone with DropBox allowed for my digital journal to be within thumbs' reach. (Though I'd later move to
SyncThing for data privacy. It runs on private home wifi.)
I've since moved back to a combination of physical and digital journaling. I use a fountain pen with invisible ink for segments I don't want prying eyes to read. As a result, I've stopped venting things I (in my right mind) wouldn't want strangers to read on Social Media, Messaging Apps like Discord, or even on my personal website. It's great. I even find that journaling allows me to cultivate and edit more raw and emotional thoughts into online posts that need to be said, but are easier for others to digest.
If journaling sounds lengthy, purple-prose-y, or intimidating to anyone here, I'd recommend Ryder Carol's, the bullet journal guy's, tutorial on how to journal via bulleted rapid logging. No rulers, markers, or stickers required. It's just a more rapid way of logging down thoughts, happenings, feelings, and actions. As someone with a history of rapid Twitter/Discord fingers when it comes to venting online, I've found that rapidly journaling feelings out has helped me a ton.
Edit: Typo