Why do my own custom character controllers cause the unity editor to lag out?

I noticed that when using the built in controller that things worked smooth (but I could not get my character to animate properly. It would just violently shake around its center point (I have no explanation). So I decided to use the Video tutorials and create my own animator controller from scratch - the animations seem to work properly but now my game is lagged down to a miserable 3 fps when it was pulling 58 fps on the stock controller. I'm reading about time.deltatime possibly being a culprit but I havent changed my scripts at all so I'm a bit lost/confused as to what to do to fix it.