Found Lump in Armpit of Breast

After taking a shower I'd exam myself in the mirror being depressed with my weight gain when I'd noticed a lump in the armpit of my breast. I found myself saying 'hum what's that?' It felt like a round hump sometimes annoying and other times hurtful. It's a soft round lump looking very ugly as it looks like a third breast hanging. It hurts upon pressing down, shaving my armpit, putting deodorant, and showering in that area. DH notice it after we were intimate a few times but I don't like to be exam as I know I have flaws so I brushed him off. Both mothers don't know about it. My mother is known to go blabbing endlessly making the problem public knowledge to the whole world as then the whole world can give me a sympathy party. My mother’s maternal family houses a history of cancer as well as Nick’s maternal family. I don’t know what it is but will get it checked out.

Now that I’ve notice it now I’m conscious of it. I'm worried and having trouble sleeping as this year starting out wasn't that great with a job loss and now this. I'm only 29 pushing 30 which I thought that breast cancer for women has a greater risk of ages 40+. Anxiety won't leave my stomach.