I would actually caution AGAINST putting cabbage against your breasts. As soothing as it may feel. Since cabbage is actually used to get people to Slow or Stop lactating. I don't think it's a risk you should take at two weeks in. Since you are still needing to regulate your supply.
And if they didn't give you a script for pain meds I would at least take some motrin before you try to nurse on the infected breast. So that you are able to work through the pain.