Movable lump in breast but I can now feel lump in armpit

I have a lump in my right breast behind nipple, I went to see a private consultant because I'm now 3 weeks into a 2 week referral and I am terrified, he told me that he didn't think it was anything to worry about. I now have an appointment for a mammogram this week, but yesterday I started with a pain in my right armpit and I now think I have a lump there as well. I am absolutely petrified that I have cancer. The lump in my nipple moves and the consultant thinks it's just a nodule but obviously reccommended mammogram.Everybody tells you to stay positive but it's very hard.