large swings in play

[JackSchit20]

I am experiencing large swings in my play. I have read the Hold Em for Advanced Players book and feel I have a good grasp on how to play solid hold em, however I seem to run into these drastic swings of play. For example, I will play 1/2 tables on PP and make about $75 in an hour session, and then the next time is sit down at a table I will get a lot of second best hands. I feel like I go through these swings of brilliant play and then horrible play. Any suggestions?