Make sure you are viewing the correct eBay account if you have more than one.
If you deleted items from your Watch List, I do not think there is any way to undo that action directly.
You may be able to find some of your previously watched items by checking your Recently Viewed list to add those items back to your Watch List. You should see up to one hundred of your most recent listings viewed.
You may be able to recreate some of your past searches to find the items again. Use your browser's history to view previous eBay pages you visited. If you use the eBay app, the app keeps track of your most recent searches.
Use the Advanced Search page in your original browser to see if your browser has saved your search keywords from past searches by clicking on the search field on that page and seeing what appears in the drop-down under that search field, or type the first letter of a search term to see all searches beginning with that letter or number.
