Glad if I could be of any help. Take a good look at the workflows and see if the results help you solve your issue. And again: check and maybe explain your text preparation beacuse the whole ‘magic’ rests on that 
It is also good to check a few random items you know the real answer by hand or let some experts check it. Model building shifts more and more from high fancy statistics into software engineering, at least for a lot of people who are not at the forefront of developing new algorithms it seems. But understanding your data and asking the right questions and interpreting the answers will not go out of fashion any time soon.
In your example now you have two categories and you measure an accuracy just by the prediction. If you move further you might have multiple classifications then I would advise to look at metrics for multi classification problems like Log Loss since it also takes into account how confident/close the prediction was. If you have time you might want to read these entries: