I felt so angry... and I still am.. I know it's stupid but I use reddit to vent without being judged or feel bad, I feel secure in posting how I feel because I know I wont have to deal with others crying or trying to make me talk. I feel naked, like my feel of privacy was stripped open...

What privacy, though? They weren't private. They were posted openly on the internet for other people to see.

Now I'm thinking about other places I vent, I'm thinking if my mom read my journal or got into my computer and saw my dialogue with people...

It's a big leap from reading your public social media to stealing your journal or breaking into your computer.

My advice? Stop posting personal stuff online if you don't want people to see it. The internet is not private. It never will be private. Your expectation of privacy was not realistic, and you need to overcome that.