Why is my lumpectomy recovery so painful and difficult?

Had my lumpectomy on Thursday. Developed a hematoma before I was even fully awake in recovery. Took me back in and removed 300cc of blood and had to stay overnight in the hospital. Sore on day 1 post surgery, better on day 2, day 3 my breast swelled up twice the size, throbs constantly and pain pills don’t touch my pain. Ice packs don’t do much either. My dr said it’s probably a seroma and she’s going to drain it this morning. She promised me I would feel as good as new. I have read so much about what a breeze lumpectomy is. I am having a horrible painful experience. Thank god for my husband, family and friends and this wonderful site full of of experienced and caring people. I am the most depressed since my diagnosis in May.