Does st. John's wort or rescue remedy help with anxiety?

Perhaps. St. John's wort (hypericum perforatum) has been shown in clinical trials to be effective for mild to moderate depression and may also help with anxiety. Rescue remedy, which is a proprietary blend of flower essences also be helpfu. Passionflower (passiflora incarnata) is another natural remedy that has a long history of use as an anxiolytic agent worldwide.
Depends. If you have mild anxiety, it might help but if it is a more serious anxiety disorder, you may need stronger medications. In any case consider cognitive behavioral therapy, which can be extremely helpful.