Of course you are worried! Michelle has given you good advice--the breast care nurse is the person you need to contact now; don't wait for someone to set it up, it's something proactive you can do now.
@soldiercrab is our lady with all the handy links, I'm sure she will put them up for you.
Regarding taking time off work, it's impossible to tell if you will need to or not. Some people work through treatment but that depends what is recommended and how you cope with it as an individual. It is worth checking to see what insurance you do have, that can make life a lot easier if you need to go through the full performance. These things are never convenient--I was 43 when I was first diagnosed and like you I was just getting my career together. That ended up being OK and I kept things on track but the whole business was a nuisance!