Just tell your instructor about your issue and skip the rolls during class. We tend to do backrolls/forward rolls only during warmup.
Actual jiu jitsu sparring doesnt cause a roll very often, and its really your choice.
Everyone develops their own personal style of "rolling/sparring" in jiu jitsu.
There is a lot of variance.
Your style will simply not including rolling.
I was a karate black belt when I started BJJ. Got my butt kicked by the white belts like I knew nothing. It was ego shattering and an eye opener.
DO IT!