Swollen left breast with lump

Hi all, sorry if this is a long post but I’m terrified. I am 42 and  2 months ago my period was 15 days late which i put down to being in perimenopause in that time my left nipple was quite painful on the run up, my period did come and all was fine fast forward to the following month my period arrived on time last Saturday and lasted around 5 days on the run up to that period I started to feel tingle sensations in my left breast and since my period ended I noticed my left breast has swollen feels tingly and has burning pain in the breast itself and nipple. I then went on a sunbed which I know isn’t good for you but was to try and get a base tan for holiday and when I got off I noticed a strange looking skin mark on my left breast I felt it and I could feel a lump which is on the inner quarter of my breast about 4cm away from the nipple, my breast feels hot to touch and have had shooting pains on and off, also my tail of spence area has swollen, I seen my gp yesterday who has straight away referred me to the breast clinic and now I’m up the wall with worry, I have family history of breast cancer my mum was diagnosed at 55 with Hormonal cancer behind her nipple I’m so scared I can’t eat or sleep