Hi
What exactly do you want to achieve?
What is the purpose of this file?
Why do you need to convert it to sheet metal?
I see several possible solutions, but I need to know the exact purpose of the geometry to show you the optimal one.
P.S.
1. You click as much as the geometry requires. Writing that you do not want to model will not motivate others to help. If you don't want it, why should others want it for you?
2. The rounding is done incorrectly. Outer radius = inner radius + thickness. With you they are equal; this is an error that will cause problems at a later stage of modeling, and finally in production.