The Adobe DRM system which is part of the Overdrive system used by most libraries is somewhat flawed,
and its implementation in ADE2.0 is highly flawed.
It is not suitable for use by computer professionals, let alone by the target audience for eBooks.
One good part of the system is that at the end of the load period books will automatically expire.
This doesn't help if you want to borrow more books and are at your limit, but at least it means you won't be charged for overdue books.
One thing that will help is to make sure that your copy of ADE is properly registered with an Abobe ID.
Don't let it run 'without Adobe ID' (I forget the exact terminology thy use).
If you are already running that way, go to the Abobe site to get a free Adobe ID.
Then completely removing any authorization using ctrl-shift-D to ADE (cmd-shift-D if on Mac).
Restart ADE, and then reauthorize with your new Adobe ID.
That seems simpler at first but least to lots of issues later.
It probably won't help you return the books you have already borrowed, but should help in future.