You are not dying @Itsok. It is normal to be frightened of getting a biopsy. It's the unknown. I had family who died of breast cancer after dealing with it for 20 yrs. That was some time ago. Treatment is great these days and most women survive breast cancer.
I could not feel the lump I had either. I am so glad it was found early. My lump was 18mm so a bit larger than yours. Early breast cancer is treatable. I was diagnosed in 2020. I had treatment and now I am on hormone suppression therapy.
At this stage you don't even know what it is. Waiting to find out is hard and stressful. Breath deeply and often. Keep busy so you don't think about all the what ifs. It may be a cyst or it may not. But at 1cm it is it has been found early and that is a good thing. Stay away from Google. Do things you like.
When is your biopsy? Do you have someone to go with you for it and to get results. It helps to have someone there because if you are stressed then processing medical information can be difficult.
Take care, breathe