Translation:I cannot go, nor do I want to.
The second negative to go with "nor" does not have to be neither. I would say, "I cannot go, nor do I want to." The "not" in "cannot" is the negative that goes with "nor." I am an English speaker, and none of the other solutions work. Soglio captured the idea that the second negative doesn't have to be "neither," but his solution doesn't sound quite right either.
"Nor" must be used with a preceding negative, but that needn't be "neither." See http://www.merriam-webster.com/dictionary/nor In this sentence, the "not" part of "cannot" should suffice.
"Neither can I go nor I want to" isn't quite right, however. "Neither can I go nor DO I want to" provides the necessary parallel between the ancillary verbs ("can" and "do"). At that, the structure strikes me as rather awkward, but I think it's correct.
I can see that "I cannot go, nor do I want to (either)" is a correct translation of the Italian but surely the English "want to" is short for "want to go"? I put it in full: "I cannot go, nor do I want to go either" and I was marked wrong for the word "go". Is there an alternative Italian sentence that would match my version?