Stress and anxiety can create all sorts of reactions in the body, skin outbreaks being amongst them. They can also occur for a number of other reasons, including hormonal changes and digestive trouble particularly if dietary intake has been suffering or the bowel not working optimally (especially if constipation is involved). The skin is one of the last resort detox routes for the body if the others (kidneys, liver, bowel, lungs etc) are not working as efficiently as they should.
At 50 you may also be experiencing peri menopausal symptoms when hormone levels naturally start to drop. Anxiety is not uncommon at this time as the nervous system falls under extra pressure. Do take a look at Eileen's blog for great information about many of the menopausal symptoms.
If you can tell me how long the anxiety has been going on and what sort of anxious symptoms you are suffering I can hopefully suggest a suitable herb. You could also try a good magnesium supplement such as magnesium citrate and take this daily in the evening to help relaxation.
For your skin, it may help to give the liver some support (provided you are not suffering with constipation in which case it is better to tackle this first) with the herb Milk Thistle for a month or so, following the dosage on the bottle and drinking plenty of water whilst cutting down on sugary snacks if you are keen on them.
You could also apply Echinacea Cream topically which I have personally found very helpful when my skin becomes spot prone!
With best wishes