I'm so sorry.
I know it's hard but the best thing you can do right now is to try stay calm and wait till you know more.
My mother first had a breast cancer lump removed 14 years ago, aged 41. It was caught very early and she had a course of radiotherapy after the surgery with no further issues at all. She went right back to living a normal life.
Fast forward to just July last year and she was diagnosed again with breast cancer after experiencing some back pain. Unfortunately it's now at an advanced stage, so technically 'incurable' as such but it can be treated and managed. It was a massive shock to us at first as I think we all assumed that after 14 years that she was definitely 'cancer free'. I guess there's no guarantees with this vile disease and every person is different but the doctors seem optimistic that she has a lot of good years left in her yet, particularly since she's responded well to medication so far. She takes 2 tiny tablets a day, goes for scans every few months and that's it. She's about to go on a cruise to NZ with my Dad as well. There are LOTS of stories of people living for years & years with this disease.
All the best for the days to come. Feel free to PM me if you'd like to talk as I've definitely been where you are right now (twice!)