Found a lump in my breast, worried about what it could be

A couple weeks ago I found a significant lump in my breast (around 2 inches across). Finally got a mammogram and ultrasound scheduled in 2½ weeks (I have extremely dense breast tissue so ultrasound is standard for me). I already had 1 fibroid found in my breast through imaging, but have never been able to feel it. And my mother has had them as well. I'm sure that's all this is, but a few months ago we lost a really close family friend to breast cancer, and that is ever present in my head. Being able to actually feel it is contributing to the stress. I guess there's no specific question, just been keeping any worry to myself so I don't worry the family.