It isn't so clear that it's not a duplicate to your question, since you have very similar symptoms to the linked question. You said, in the comments to your question:
See my post (edited) for the output of the commands suggested in that answer.
However, that answer wasn't linked. A question was. It had more than one answer. You're supposed to go through all of the answers to see if any of them solve your problem. Since some of the answers teach how to use the packaging system's tools to identify the source of the problem, it's unlikely there is no answer that would have worked there.
If you still felt your solution wasn't included there in some form or if you think it's easier for future sufferers to see an explicit solution rather than letting them rely on generically learning how to use the packaging system tools, you could add it to the answers there, so that that question becomes even more of a resource that we can use to mark questions duplicates.
It doesn't make sense to have 25 questions that are essentially describing the same symptoms but each with a different solution as an answer, since remembering them all and including them all as possible duplicates each time someone mentions the same symptoms in a new question would be wasteful. If instead there's one question that has 25 potential solutions to some symptoms, it works out better that way, since we can remember and link to just that one question, and sufferers can check all the answers out.
Alternatively, you included a link to an answer from yet another question in your answer to your question. You could have flagged your question as a duplicate of that question.
apt-getcan and does "fail" in many ways & for many reasons. Looks like this post should be added as a duplicate target for your question: dpkg error: "trying to overwrite file, which is also in..."