I just recently uploaded my first CPAN module too (Algorithm::BinPack, in case you wonder). Interestingly, my experience was a bit different from the one you describe. It was kind of fun and exciting, if such words can be used to describe the process of uploading a file to an archive. Building a nice test suite was an interesting challenge for me, and I was pleasantly surprised by the automated testing done by testers.cpan.org. My carefully crafted test suite passes on 6 different platforms! That's satisfying.
I wasn't terrified of making mistakes, either. Everybody makes them, and unless they cause the death and/or destruction, they're only truly bad when you don't correct them. For instance, when I uploaded the 2nd version of my module, I accidentally broke the test suite. Silly me! I forgot to check it before uploading. So I fixed it, and uploaded another version. No big problem, just a bit of egg on the face. As long as you're willing to correct any mistakes and move on, I wouldn't worry too much about getting your upload perfect the first time.