Not that it has anything to do with your problem, but you might want to consider not using a string to nose anchor if you’re also using an index finger to corner of mouth anchor. I believe using both will throw you out of alignment and cause you to not rotate your head as far toward the target as you should.
People who use a string to nose anchor usually also anchor under the chin, an anchor that is further to the left (RH shooter) than a corner of mouth anchor. Olympic shooters like this anchor because they shoot at longer ranges than we usually do.
If you intend to do a lot of shooting in the 15-25 yard range, you might want to use your middle finger rather than your index finger in the corner of your mouth. If you like a nose anchor, you might consider using a cock feather to nose anchor rather than a string to nose anchor, which will move that arrow further to the right and give you better alignment over your corner of mouth anchor.
I find that practices that are awkward can create mental issues that possibly can lead to target panic, if you try to force yourself to continue to use them. Your body is trying to tell your mind that something you’re doing isn’t right. Actual target panic usually doesn’t show up in the early stages of an archer’s career, but plain old nervousness and stress certainly might.