It depends on how you personally define them.

In one case the possibility of content seems to be affirmed and in the other denied.

Solipsism is the belief that there are no other minds. Epistemological nihilism is the view that we can't know anything.

Solipsism is the belief that there are no other minds. Epistemological nihilism is the view that we can't know anything. — Purple Pond

Solipsism isn't just the belief that there are no minds, but that there is no external world - nothing beyond my own experiences - anti-realism.

Both are incoherent and defeat themselves, or at the very least require a new definition of "knowledge".

For one, if we can't know anything, then how do we know what Epistemological nihilism is? In solipsism, "mind" (the one thing that a solipsist claims to exist) becomes incoherent.

Am I correct that there is also global skepticism which would be in between solipsism and epistemological nihilism?

Ontological solipsists are saying that they definitely know something. They're not saying that knowledge isn't possible. What ontological solipsists know is that only one mind exists.

Epistemological solipsists are saying that they don't know a specific thing: whether anything exists other than their own mind. They're not denying any other knowledge.

Epistemological nihilists are saying that knowledge isn't possible period. Arguably we could say that epistemological nihilists are simply saying that knowledge isn't objective, but on the standard definition of knowledge and a standard philosophical sense of the subjective/objective distinction, no one should be arguing that knowledge is objective, unless they have a very weird ontology where beliefs can somehow obtain outside of minds.