my forum is back up and running. in order to summarize this whole process and what happened for anyone who experiences the same situation, here's what happened:
My forum was at version 3.2.1 and I was notified that my version was out of date and in need of an update via the ACP. it said i should update via the automatic update package.
i downloaded the automatic update package and followed it. it hung at 3%. i then tried to update all the files manually, but still received only a white page when trying to access my website.
following david63's advice I checked my server's logs and discovered that my server was experiencing a timeout problem, which i requested my service provider change.
after that, i could read my forum but not login and interact.
finally, i uploaded a backup of the database from about a month before, and it seems as if my forum is working now.
a sincere thanks fro all of you who took the time to try to help me!