I think by paranoia we credit outsider shills with more of an effect than they actually have.
The ebb & flow of the discussion seems to be mostly based on patterns around the type of anons who are on the board at a given time, and what their moods are at the time. For example, the composition and personality of the group will be different on a Monday night at 11pm Eastern than Tuesday at 9am, which will be different than Tuesday at 5pm.
I can see the effects over the course of a week in my own posts, when thinking back about the topics I replied to and the quality of my posts. When I'm irritable, bored, or impatient I am more likely to pick an argument or comment about a low-importance issue. When I'm focused and inspired, I spend more time doing my own research, creating memes, and finding high quality posts to read through instead of making casual responses.
But anyway, even if you only get one positive comment, remember that there are probably hundreds of anons that saw your work and appreciated it.