Drive full and can't delete

Hi my 2TB drive is full ( I didn’t realise this until I tried to use it) anyway, it now won’t let me delete things off it so I can use it. I’ve just tried the mac first aid but it can’t complete and now disc is not being recognised. Do I need to take it to a computer shop or can I access files to delete so i can use it again ?

If First Aid could not complete a health test then the reason why you are unable to delete files is because the volume itself is damaged or corrupted. If the unit can not be formatted in the Partition Tab of Disk Utility then it would be best to replace the entire unit.

That doesn’t sound good, I might take it to a computer shop and see if they can resume the files that are on there.
Thanks for your reply