Trying not to panic

Hi,  I found a lump in my right breast the Friday before last, went to the doctors who referred me on the two-week pathway and so I’ve got an appointment at the breast clinic this Thursday; where I’m told they’ll do mammogram, ultrasound and biopsy, if necessary. My lump feels like a ridge and I was ok about it until the doctor felt it too. I’m trying not to panic but it’s always there, at the back of my mind, especially at night so I haven’t slept well since I found it. My husband is super lovely and I know he’s trying to be positive and not to be worried but it’s very scary for us both.