Sorry you had such a rough start. I have a fairly good idea what you are going through. My first nine weeks of breastfeeding were very painful (was in tears every feed), and I had mastitis twice during that time. After that I still got blocked ducts every now and then. The one thing I found helped was to keep feeding. That and a hot water bottle. As somebody said before, there are no 100% guarantees for this (or anything else in this world). Just go for it, and good luck to you!