ANXIETY!

I’ve just recently been initially diagnosed with DCIS but this will possibly be upgraded to invasive, they are doing further testing on the biopsy. And my anxiety is through the roof, I have so many physical symptoms - heart palpitations, tight chest, pains all over, difficulty breathing, can’t eat and not sleeping well. All these symptoms are making me think that cancer has spread everywhere. What can I do? I have 2 young kids and can’t function. Does anyone have any coping strategies?