Who found their own 'lump'

Hi I found a lump in my left breast a week ago its the size of a pea. My doctor felt it too and sent me for a mammogram and ultrasound. I felt humiliated when I was told nothing showed up. I also have itching burning sensatins where the lump is. I dont feel well, constant nausea, dizzy spells and general feeling of being unwell. I hate feeling like this and  I know something is not right but Im not being taken seriuosly. I have an appointment Monday 15/12? 14. Im not going to let this go because my step mum had the same problem and she has just had a mastectomy for 2 types of breast cancer. I am scared witless at this moment.