Hi there,
it is indeed a very personal decision.I had a mastectomy of my left breast as the lobular cancer was so large .I had a reduction in the right breast ( was an E cup now a C cup) and I am really pleased with it.I opted for a two stage reconstruction of the left breast with the tissue expander inserted during the mastectomy and after radiation I will have that removed and the operation for the diep surgery ( from my abdomen).
As with all surgery it will not be without pain and discomfort and the recovery is not a walk in the park.But people I have talked to in person or online about it think it was worth it in the end.And I think it’s a bit like childbirth, as time passes the memory of the pain lessens .And they have plenty of good pain meds.
As an E cup I couldn’t contemplate going flat on one side as it would have been so weird but I understand that many people are ok with going flat,
which brings me back to the first point about it being a personal decision.
the other resources suggested in the above posts are well worth a look.
best wishes for the operation and recovery.