Because of his overweight, Steve got a nickname

[Bassim]

I am wondering if my sentence is grammatically correct.

Because of his overweight, Steve got a nickname "Fatty" in high school, which still grated on him twenty years later.

 

[emsr2d2]

In addition to RoberJ's changes, I'd probably say "Steve was nicknamed Fatty​".

 

[GoesStation]

Or "Steve got the nickname 'Fatty', which still grated on him twenty years later." I removed the first comma.