Your description is very unusual; it may very well be that the lesions that you are currently experiencing are not related to the breast reduction procedure done 8 years ago. I would suggest that you seek consultation in the near future.
You need to see your doctor. It can be a few things. We use observable sutures that our body sometimes does not let our skin heal. Without an exam we cannot diagnose what can be going on with your incision. You need to have that checked a.s.a.p.