Can long term stress and anxiety trigger trigeminal neuralgia?

Yup.: Seems that stress and anxiety are multi-talented evil-doers. They can, indeed, trigger and aggravate trigeminal neuralgia attacks. This is another good reason to do some CBT therapy to learn skills to avoid, reduce and manage stress/anxiety. It is a very worthwhile investment for many aspects of your (hopefully long and good) life. Best wishes!