Don't get discouraged by it. In fact, learn from it. There are many changes with the new Hardfork and you have been affected by one of them.
Using bidbots or paid for upvote bots have been frowned upon in the past and now that people have a bigger voice because of their free downvotes they will speak out and react if they think the post is not worth the payout. While this might seem unfair it is done to balance out the system overall and make it more fair for everyone.
In the future, use the payforvote bots a little less or with smaller amounts. Or perhaps only on your best posts.