Unless you haven't updated your WordPress for a long time, you shouldn't have been able to change your upload folder through the Dashboard anyway. This feature was removed in version 3.5, if I'm not mistaken.
First, back up everything (your WordPress installation, especially everything under
wp-content, and your database). Now what you can do is:
Look for a line similar to
define( 'UPLOADS', 'wp-content\path );. This is the only way to change your media directory on newer versions of WordPress.
If you see code like that, try deleting it from
Install the latest version of WordPress
- Download the zip from WordPress.org.
- Copy the zip to your WordPress directory.
- Move out
- Delete everything in your WordPress directory except for the
- Unzip the file you downloaded from WordPress.org. You'll see a new folder called
wordpress. Copy everything from there into your original WordPress directory.
- Put back your
Ask your host to revert your site to an earlier state
This is a last resort. Just ask your host if they can revert your site to a time before you noticed your image access problem.
Whatever you decide to do, you an always restore your backups in case anything else goes wrong.