@CeeCee sorry you find yourself here. Your medical team will be doing all they can to get you in for scans and treatment. Have you been allocated a breast care nurse. If not, ask for someone in your medical team to put you in touch with one. During covid an organisation in Melbourne called "Think Pink" you could book an online zoom call with a nurse to chat with. This may be helpful. They also ran zoom meditation classes and yoga classes. I did a meditation class a couple of times but had buckleys of getting on the ground for a yoga class. It was more getting off the ground that was hard. I would have been stuck on the ground for days!
I think had a little anxiety before bc that I just thought was normal me...but now I have a much much more heightened anxiety. I do get a overwhelmed at times and I tell myself to breathe, do one thing at a time, its not a race and I have to let a few things go for my mental health. Take some time out and have a cup of tea, go for a walk, binge something on netflix. Be kind to yourself. If may mean you have to say no to others but you do need to rest and put your needs first.