Gurn,
Have you considered the string can only strike your face if your face actually gets turned into the string, or if the string, at the release, is moved out of alignment causing the bow to torque? The string will always return to the center of the bow. It cannot do anything else.
Back tension does not move the string closer to your face. Your anchor is your anchor. Back tension will move your drawing arm into alignment with the string, which is why a release with back tension is so much smoother, or consistent, than using your arm or shoulder.
It sounds, from your description, that you may be collapsing your form at the release, or losing tension which creates a "forward" release. It can be very subtle and hard to catch unless you know the feeling or video yourself from different angles and watch it in slow motion. If this is the case, pulling past your anchor and releasing will feel better and may give better results initially, but that is really just a "calculated" pluck that you'll soon lose control of.
I could be completely wrong on this but thought it might give you something else to evaluate.
Good luck.