I suggest you try these foods, as well as other foods recommended for BOTH herpes & ulcers:
broccoli (heals ulcers), olive leaf extract (if this is too bitter, mix it with very-liquidy instant potatoes), Pau D'Arco tea, acidopholus, and maybe even black cherry yogurt.
If all else fails, or if really bad, I'd try the black cherry concentrate for a few days, first thing in morning (diluted with some water and accompanied by, say, 2 oz. of plain yogurt). Also, maybe, licorice tea (not the deglyccerinated - I suspect the glycerrizin may be healing - but maybe I'm wrong about this.
So long as you realize that cherries & licorice can be estrogenic as per Julia Chang.