That point of time is now. Had you bought at the peak at the end of August, you would still be holding now 4 and a half months later. Say 1 CFD costs $2.50 to hold per night and there is 128 days from September 1st to today, that is $320 dollars in interest. It could be many many months more before you make that interest back, plus profit. Keeping in mind that interest will continue to build up nightly.
Sometimes it’s better to cut your losses and start over. I have about 90 to 95% success with the simple rules I set myself outlined above. My losses were all intentionally taken for the reason I just gave - sometimes it’s quicker to cut your loss and make the gain elsewhere, rather than be patient and wait for the stock to rise.