Such a scary learning curve

Wondering what if can bedevil us all - but it's also possible that things might have worked out differently. Some precancer cells never develop. Cancer is so variable - it's possible of course that something was missed, but it's also possible that the outcome you have now seemed very unlikely.  I had the left side mastectomy and axillary clearance over 5 years ago.  All good to date. Lymphoedema is also highly variable - some get it some don't. I did and it's proved very manageable, doesn't really alter anything I do, and preventative care is relatively simple. DON'T look at websites, particularly overseas ones - will just scare you and it's usually not relevant to treatment today and in Australia. Stats are on the side of you not getting it - but you have other treatment to think of first. As @onemargie says, things will look less daunting and frustrating once you have a plan in pace. Great that you have good support. Best wishes for your surgery - that is usually remarkably painless.