Just to clarify, private citizens don't "file criminal charges." I assume you mean that he contacted the sheriff and reported an alleged crime, that the sheriff investigated, and that you were not arrested and no charges were filed.
Defend yourself against what? If my assumptions are correct, there's nothing against which to defend yourself.
Are you talking about the 4th and 14th Amendments to the U.S. Constitution? If so, that's absurd.
The Fourth Amendment states as follows: "The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized." In other words, searches and seizures must be reasonable, and warrants may only issue upon a showing of probable cause. What does your friend think any of that has to do with the sheriff's refusal to give you a copy of the criminal complaint?
The Fourteenth Amendment has several components, and I don't care to quote all of them. However, if you click the link, you can read for yourself that it also has nothing to do with your situation.
More importantly, given that the matter is closed, what do you think you'll have to gain by getting a copy of the complaint?
Huh? Judge's clerks have no competency to opine about things like this.
You can file all the lawsuits you like, but if you filed such a lawsuit, you and/or any lawyer who might be dumb enough to take the case would run a significant risk of being sanctioned for pursuing frivolous legal action.
You have suffered no damages, so, even if what you're talking about weren't frivolous, you would be awarded precisely $0.

