Breast clinic on Tuesday

Hi everyone it's my first time posting. 

So I went to the GP last week about skin changes on my breast. It's really dry and scaly, and I have nipple discharge. They've referred me to the breast clinic and I have my appointment on Tuesday. What's likely to happen whilst I'm there? Do they always do a biopsy? I'm absolutely worried sick that it's cancer. How do people cope before their appointment? Thank you