This is what I really want, but it gives me an error:

What I tried the first time: I tried creating a Loft between Top Sketch and Bottom Sketch (for the Bottom Sketch, I didn't select the entire sketch, but just the half that faces the Top Sketch) but it didn't work. Using the Guide Line didn't help either.

What I tried the second time: I figured that maybe since the Bottom Sketch wraps around the other side of entire cylinder, I'd create a 3D sketch using just the top part of the Bottom Sketch. But it gives me the error shown above.

I appreciate any help I can get! Thank you.