WP site using too much data and got suspended by host

I got the below message from my host. The site was suspended, but they then unsuspended it so I could access it and delete the large files. They data I uploaded equal less than 3 gigs so I don’t know where they large files came from. I am pretty much a novice at this. This is the message from the host site:

The issue with your disk usage is not files in use by your site but rather the database associated with it. This disk usage is not located within your account, but rather in the MySQL directory of the server and so while it will not be reflected as disk usage within your site files it is still disk usage in use by your user that is exceeding our allowed limits. In reviewing your database we found that the largest usage of its disk space is the wp_options table and much of this disk usage is transient data. This type of data is commonly only needed for temporary usage such as managing sessions or cache however with it not being removed after needed it has accumulated to a total of 327 GB. While we would be able to assist in making deletions we would require specific instructions as to what data you would like deleted including any rows to be deleted or queries to be ran. If you are unsure of what content can be safely deleted then we would advise consulting with a web developer or database specialist regarding what content can be safely removed.’

Once the suspension was lifted I logged into the site for a fist time in a while and got this message:

‘Database Update Required
WordPress has been updated! Next and final step is to update your database to the newest version.

The database update process may take a little while, so please be patient.’

But then it said:
‘Sorry, that didn’t work.
Please try again or come back later.
503 Error. Service Unavailable.’

I was hoping the update would delete the unnecessary files, but getting the error message makes me think not. Any help would be appreciated.

The page I need help with: [log in to see the link]