Worried I have breast cancer..

I’m 20, and I have a super itchy boob with a big lump under my nipple that is super sore.

So In January I started taking birth control pills after being 4 months pp after having my son. I was on the pills up until June and I switched to the patch. After about 2 months of being on the patch I noticed I had a lump in my right boob. I thought it was the birth control so I quit the patch in September. I called my OBGYN and his nurse called me back and told me it sounds like an abscess and that I needed to go to the urgent care or family dr. So I did that, that day. My family dr felt my boob and told me it was not that and that I needed a mammogram. So I went back to my obgyn office the next day and I was in the waiting on getting a mammogram. Well my OBGYN nurse comes in and tells me to leave because I’m too young and Nothing would show up. So fast forward to today, I have an extremely itchy boob with a swollen/sore nipple and a lump under it that seems to be getting bigger but not visual. Also my boob seems bigger than my left and idk why. What should I do??

** also I have major family history of cancer and breast cancer!