Output loop in accordions

I need all the content in that loop to be held in the one accordion, as opposed to have one accordion for every item

I’m not familiar with the accordion shortcode that you’re using, but it should work like this:

[loop ...]
  [accordion]
    ..[field title], etc.
  [/accordion]
[/loop]

The above will display one accordion per item. To include all items in one accordion:

[accordion]
  [loop ...]
    ..[field title], etc.
  [/loop]
[/accordion]