Do go back to your GP. You are right to be concerned, but try not to worry too much: 9/10 lumps turn out to be benign conditions, not cancer. If you are one of the unlucky ones, the sooner you start treatment the better your chances of getting rid of the disease!
Good Luck, I hope it's something benign and easily treated, if not this forum is a wonderful place for support! xx
Hello Karlie
Welcome to the forums.
Whilst waiting for replies maybe you would like to talk things through with a member of our helpline staff who are there to offer emotional support as well as practical information. The free phone number is 0808 800 6000 and the lines are open Monday to Friday 9.00 to 5.00 and Saturday 10.00 to 2.00.
best wishes
June, moderator