Needs evaluation. "blisters" and "dead skin" on a breast after mastitis sounds like a problem. A primary care doctor can evaluate it to see if further treatment is needed, or perhaps the previously inflamed skin is now drying up and will eventually peel away, leaving new skin. The breast can be examined now and then again later, to be sure the breast returns to normal, and there is not another medical problem.
TLC. Use breast shells between feeds to keep clothes from rubbing against nipple. Sometimes hydrogels help as well. Prevent mastitis by making sure to empty breasts frequently (don't skip feeds). If pumping, try a larger phalange size. Expect a slightly lower supply on the affect side postinfection.