Mastitis or cancer lol

My doctor put me on 2000 mg of antibiotics a day. He felt my breasts and said they were warm to the touch, and also red. He said he’s almost positive it’s mastitis but was left untreated. I had no choice but to take out my piercings. I have swollen glands, mostly on the left side, none under my arms but in my neck and in my collarbone. I have sparks of pain that are in my neck, my collar bones, and my back of my neck. He didn’t feel any lumps he’s worried about, but if the antibiotics do not work, I’m going to have to get an X-ray and possibly a mammogram.