Firstly visit adobe forums, where a lot such issues and ready solutions for you, another variant is to apply Ghostscript, last one solution might be [Moderator: Name and link of questionable PDF repair solution removed]
I've tested a number of services/applications that claim that they can repair PDF files, and none of them was actually able to do that with a truly corrupt PDF file. I also would be very suspicious of a service that requires me to upload a PDF file - you have no idea what they are going to do with your file and the information contained in that file.
How are you accessing the file? Is it in a web browser? Is it on a network drive? If so, the first thing I would try is to copy the file to my computer and try to open it locally.
There is not much you can do if you have a corrupt PDF file. That is why it is so important to have a working backup solution so that when something happens to your files, you can go back and retrieve an earlier version of the file.
Let's try to figure out what happened with your file: You say you created it. What did you do after you created the file? If you did not do anything with this file, then chances are that the corruption is caused by a problem with your hard disk (e.g. a file system corruption). In that case, you have bigger problems than your corrupt PDF file. The good news is that Adobe Acrobat will actually tell you that a file is corrupt. Other applications may not do that, and you may be working with corrupt files without knowing.
If you used any other tool on the PDF file, then chances are that the corruption was caused by that tool (e.g. 3rd party PDF viewer, 3rd party PDF processor, ...).
There is a slim chance that you can restore a previous version of the PDF file by editing the content of the file. To do that, create a copy of your corrupt PDF file. Anything you do from now on is done with that copy. Open the copy of the file in a binary editor. Then jump to the end of the file and look for the last instance of %%EOF in the file. If that last instance is actually in the last line of the file, then look for the next to last %%EOF in the file, if there is content after the last %%EOF, then that's the one you want to use. Now delete everything just after that %%EOF and save the file under a new name. Try to open that file in Acrobat. Does it work? If so, you recovered the previous version of your PDF file. If it does not work, then unfortunately you ran out of options.
If pdf document can't be opened, then try to open it with the help of another version of Adobe Acrobat, if not, check backup copy of pdf file. If both methods aren't effective then you may apply [ Mod: link to questionable online service removed ]