So I went to the GP 10 days ago with a small lump under my nipple, just next to where I had a benign tumour removed in 2009. He referred me to the breast clinic, and over the week that small lump turned into a HUGE (orange sized) hardness encompassing my nipple and a triangular wedge shape in my under boob. He put me on antibiotics for lactational mastitis (I’ve not breastfed in 2 years) and after 5 days of no improvement I went back yesterday to have the antibiotics changed. 
I’ve got the clinic on Saturday but I’m absolutely freaking out.

I had a heart condition diagnosed in May so I’m scared that it was the precursor to something horrible?! But I don’t see how it would have grown this much in 10 days…?! Also I had 3 CT scans when I was getting my heart diagnosed, the most recent one was about 6 weeks ago, could a tumour have appeared so fast?

I’m noticing swelling after I take my bra off, like a fluid pooling kind of thing…

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Also a little warmth in the hard area. But no rash, itching, oozing etc. 

Has anyone had these symptoms before with a positive outcome?