You were targeted by someone and they used the bots to punish you. It could have been a keyword in your posts. I had some tool that would down vote any post where I used the word snowflake. I guess the little snowflake didn’t like me calling him one. I played around with bots for a while but it wasn’t worth it. I was a OP on several IRC networks back in the day and the bots we ran then actually did something useful. Like a small percentage of reddit bots.
Its still there. I like it and sometimes when its tech related its the best place to go to get reliable information.