I would strongly recommend removing all attachment fields (and any other MVF fields)
Basically you need to store the files outside Access and store just the file path in Access with a separate record for each file.
This will drastically reduce your database file size and should improve performance
If you only have a few attachments, it is easy enough to start again using the above approach
However, if you already have a lot of attachments, you may wish to automate that process.
Doing that is a separate topic in itself which needs its own thread.