The extrusion gives an error (unable to create this extruded feature due to geometric conditions.) when the sketch is like I want it to be, which I think is due to the corners at the top. When I bring those two corners closer and effectively their angles larger, it works BUT, it's with a catch.

Not only aren't the upper corners where I need them to be anymore, the extrude also looks ridiculous, not at all like I need it to be.

When you look at the cilinder in the middle, I need all the lower edges to have a gradual emboss (or whatever you call it) towards it. It needs to be one solid part. I think the way I sketched my 3D sketch should give a good idea of what I mean. However, the extrude has a very strange bulge that is very unwanted, and not only that, the extrude only works when the sketch is not like I want it to be.

Does anybody know a solution to my sketch problem? Or an alternative way to fill up that area which I have sketched?(and all the other corners). Those areas need to have a slight curve as well, but I figured that this should happen automatically due to the radii that the sketch has.

It's a very simple shape, and I feel like this should be able to get done very easily, but my skills are seriously lacking here... :-\

Thanks in advance.