Hiya . 
Having read your post a couple of times I really can feel your pain and distress . It's a rubbish time for you and I think everybody on here will agree that the start and maybe a bit beyond until we have answers are the most difficult times of our lives so far . 
Waiting for appointments, tests and then the results is mental torture and everybody reacts differently . For me this means mainly being strong and outwardly coping whilst inside having an absolute meltdown . I wait until the house is empty before I completely go to pieces . After I'm done I feel better . It's like a slow build up , boiling point , explosion , level off then start again ! I find in the days leading up to appointments are the worst and that's when my anxiety rears it's ugly head . I have never suffered from anxiety before so it's a bit of a double punch in the face if I'm honest . 
I knew I couldn't cope mentally at work until I had all the answers and thankfully my employers have been absolutely fantastic in supporting me and have allowed me extended leave .the negative of that though is that I have a lot of time to think which may be a good thing or a bad thing . 
have you spoken to your GP about your anxiety over this ? They may be able to help you until your appointment date ? With me 3weeks seems to be the norm for appointments /tests and results . I'm still in the planning stage even though I was diagnosed with ILC at the end of November but theres been a few curveballs chucked in there to stop progression to surgery so far . I think once they have all they info they need they are pretty speedy no matter which part of the country you're in , but it's the getting to that point that's absolutely soul destroying . 
If you want to chat anymore give me a shout  and I'll help as much as I can . Xx