Has anyone had gastric byp with a BMI around 40 and weight around 230?

I'm having gastric byp in 2 days..my BMI is 40 my weight is 230..been on this pre op diet of 4oz protien 4oz veggies 4oz fruit n 2 protien shakes daily since friday. I've cheated here and there with littles bites of this n that cuz dammit I'm hungry..I know I'm kinda small to be doing this surgery but I'm doing it for more reasons..I want to know has anyone else this size..by the way I'm 5 foot 4 inches..had the RNY gastric byp, how did u do on ur pre op diet? How was ur surgery expirience and results? My nurse made it sound like since I'm young, 23, and BMI of 40, my liver should be small enough n I should heal fast. Is this true? Help I'm scared.