Performance issues with Alienware R3 15

Since purchase I can't the 1 game I want to play, Overwatch. After a game or two my laptop will drop in performance and overheat. It reaches temperatures like 86-90 F even when I run the internal fan in performance mode. I also bought an external fan but that won't even help. I can't play most if not any video games on this laptop because it will overheat and drop my FPS to 10-25.

A second issue I have is that if the laptop isn't plugged in I can't use the laptop. Every part of it lags. I can't load youtube videos or look at my feed on facebook. It doesn't open programs quickly or at all and I am unable to figure out why. Web pages fail to load and video games aren't an option. I understand that a laptop needs to be plugged in to perform, but it can't handle simple tasks when not charging. 

Before you comment, know that EVERYTHING is updated. All of my programs and settings are up to date. Every time I contact support they waste hours of my time updating my drivers that don't need updating!! 

I've had my entire cooling system replaced and had this laptop REPLACED. I need REAL solutions ASAP.