In such a scenario, your best plan B would probably take the form of having a real job offer in hand with another employer before you have your talk. Not having a backup plan, you have given your abusive boss to raise much more for you because they know they have nowhere to go. Having a plan B, however, empowers you with the ability to walk out at any time negotiation should not go right. Increase the power and have a plan B before addressing the conflict. 2. Never react to verbal abuse or harsh criticism with emotion. It always will get you into more trouble than they started with because it will become a war between egos and chances are good that your boss has a bigger ego than you have, hence why it is difficult in the first place. When a personal attack is made on you, they are trying to bait you into reacting emotionally because once you react, you become an easy target for additional attacks.
The key then is not to react, but to acknowledge and move on. In doing so, you effectively strip all the power behind their verbal attacks away from your abusive boss, without creating conflicts. If your boss happens to be a bully or a control freak, then the best way to deal with their behavior is to remain calm and acknowledge their power, saying: "You're right, sorry." In saying this, they remove any possibility of returning to whip you because you have shirked their verbal attack rather than meeting face to face.