I accidentally deleted a playlist in Apple Music... Can I get it back???

Unfortunately, there is no way to get a deleted playlist back.

However, if you sync your music to your computer via iCloud Music Library, there is a chance that the request to delete the playlist has not been pushed to the computer, in which case you could turn off WiFi on your laptop to stop it from receiving this request and note down the contents of the playlist before it deletes when you turn WiFi back on.