Hi
From what you are explaining you accidentally deleted the survey on your local computer AND the survey as it was published in ArcGIS Online.
Survey123 does warn that it will delete the local copy and the AGOL versions of it though:
Normally if i want to delete a survey I click on the three dots of a survey, then choose Open Folder, then delete the folder locally on my computer:
You will still have the survey on AGOL and can download the design files if you need it.