Well, if your files have been deleted for six months on your iPhone SE, there is no way for you to recover your files. Even if you have enabled iCloud Drive, it can only help you to hold on to the deleted files for 30 days.
If possible, you can send your iPhone to the local professional office to ask for help. Or you can go to the Apple official website and then turn to Genius Bar to check whether they can help you recover it.