Insulin overdose?

[scooch]

Hello, new member here. I am worried I took too much fast acting insulin and now I'm afraid to go to sleep. My sugar has been running high all day. I called my doctor and she told me to use this sliding scale: 200-250, 18 units, 250-300, 20 units. In the past three hours I've taken 36 units. Is this enough to overdose and has anyone heard of this sliding scale she gave me? I'm very confused about this.

Thank you!