can't log in any more

I installed Gallery, configured it and and posted a lot of photos. All seemed fine for a year. Now I can't log in even as admin. I haven't tried in a while, but I want to add some content. It appears that maybe there is a corrupt session. I actually got past the login a few days ago and started researching the output through the code, but I can't recreate it today. I just get a database error if I ask for a new password or follow the 'back to gallery' link.
I don't know if this is the reason, but at one point, the login was showing up in Firefox in my Wordpress login dialog. I would then change it to the Wordpress log in, and that would work. Could there have been a crossover through a cookie? Also, I did give a special login for a client to have a private preview of one of the groups of photos, and you can't get into that either, though you can view the one that is not password protected.
The address is http://www.papillonweb.net/gallery2/main.php
All I really want to know is if there is a way to reset everything so I don't have to restore all those photos to use the gallery.
Thanks,
ella