Welcome @Sarnicad . The diagnosis is overwhelming isn't it? One minute you're travelling along fine, making plans and the next, you're completely sidelined. I think it's so hard that at diagnosis most of us feel completely well - it's the treatment that changes how we feel.
To repeat @kezmusc, get yourself a gatekeeper or two for passing out info - you have enough to deal with, emotionally. My husband helped with telling family. I told my manager at work, who of course had been aware of the breasts teen recall. I rang two of my closest friends (from different friendship groups) and asked them to contact others and to tell people not to call me at that stage - all if the info was passed through these friends. A little later, my husband helped me set up a blog and I have used this to keep people updated, as a kind of diary of my experiences, and as a document of my thoughts and emotions. I gave family, friends and colleagues the link for it - it's both private and public - it's off-search-engine but I don't mind who sees it if they are interested in my progress or if my experience can help them.
You are not alone in this. This site has been a source of information, support, the odd laugh and a general sanity saver for me and many others across the country.
Try to take things one step at a time - we're in it for the long haul.