Seeing as I'm a figment of your imagination- there seems little point in replying. Still- for what it's worth. Yes- we all live inside our own heads. My perception/interpretation of you and everything else is unique to me. Same as yours is to you. My perception of you isn't you though. Neither is yours me. It's an interpretation of something real. It doesn't change reality. You're post still exists- whatever people happen to think of it. The only reason it wouldn't exist is if you didn't write it, you deleted it or- a mod deleted it. In which case- it still would have existed for the short period of time it was online.
If I bought a massive encyclopedia new and unread from a bookstore and dropped it on my foot- I imagine it would still hurt- right? Books don't need to be read to be physical objects in space. If someone hasn't read any of your posts or heard you speak or even seen you- they could still walk into you on the street.
Our interpretation/ perception of one another only influences how we would treat one another. You still existed before you joined this forum and we all started reading your posts. If we didn't exist, our problems would be solved and we wouldn't feel the need to kill ourselves! I imagine a lot of us would feel very envious of you if you don't exist. Congratulations!