Large, hard immobile breast lump

Hello all

About 6 weeks ago I found I very hard, boney, immobile lump in the upper, outer quadrant of my right breast. I'm 34 and a student who has just sat exams, meaning I put off seeing anyone for a while. However my husband finally convinced me to see the gp, which I did 3 weeks ago. She felt the lump immediately and estimated it to be 2-3cm. She said she would refer me on the 2 week pathway to the breast clinic. I recieved an appointment for 2 weeks, 5 days time, which is actually this Friday 31st May. She told me to wait to see if it settled following my period. I actually had my period around a week after seeing my gp, and although my breast did decrease in size slightly, the lump actually became harder and easier to feel. So I don't think the lump shrank, more like the tissue surrounding it decreased making it easier to see. I'm so scared, literally petrified. Im sorry for the long post, I know no one can tell me what it is, or isn't I guess I just needed to speak with people who understand. I'm so frightened x