Breast Lumps

After having 4 clear mammagrams the last one been 9 months ago  i fiound a lump in my breast. Whilst in the bath. I went straight to the doctors and she examined me and referred me to a breast clinic. I have my appointment in 2 days time and im  absolutely terrified. My daughter is terrified also because i lost my husband last year. So she is worried about losing me as well. I cant get it out of my head and havent slept properly since finding the lump. If this is serious i wont cope wiith it very well.