May be this is because I am not 21 anymore and has started valuing my time but to me it looks like I am DONE with toxic clients (there are at least two with us). They ask for everything, pays less/late and undermine work and cost.
I am also seriously thinking of changing the way I work and the business model (I am already working on it but will take few months as I am starting from scratch and learning lot of new technologies on my own).
If you are running a services businesses, here is my honest advice – Leave toxic clients right now, tell them NO. The sooner you do, the better it is.