When breast tissues are surgically cut during breast lift procedures, skin flaps on the lower poles of the breasts (adjacent to the vertical incisions) and the nipple areola complexes can have some impairment of circulation. Superficial layers of the skin can die, causing blistering and delay in healing, but ultimately healing just fine. Or, larger areas or the full thickness of the skin or areola can have inadequate blood flow to survive. In these cases, your surgeon may ask you to help the healing along with dressings you change frequently as the scabbing and dead layers come away and are replaced with healing healthy tissue. True, this may mean somewhat more scarring, but you have scars already, and these usually do heal just fine. In rare cases where the amount of skin loss is greater, additional surgery may be required, but ultimately still ending with a good result! You have beautiful shape early in the process, so your surgeon has done a skillful job with the procedure; unfortunately, your surgeon cannot increase the capillary blood flow to your nipple.
However, if you are a smoker, or expose yourself to second-hand smoke, or use nicotine gum, spray, or patch, this is absolutely harmful to your micro-circulation, and should be completely stopped immediately! This is something I require of every one of my surgical patients because of the 15-20% possibility of this kind of ischemic healing concern in smokers. In non-smokers, these kinds of circulation impairments can still occur, but are much more uncommon (around 1%). Bleeding, excessive swelling, too-tight closure, or too-large implants (when used) can add to the healing difficulty.
Be patient, see your doctor frequently, and follow his advice. You WILL have scars, and they may be slightly more on the side with the discoloration, but "horrible" is just plain unlikely. Keep things clean and call your doctor if you note signs of infection (increase in pain, redness, swelling, or purulent drainage). BTW, bad scars can be revised, so you still have a "safety net" if things aren't OK as time goes by.