What to do about seems to be an infected seroma? Surgery was June 26, 2018.

About 3 wks ago i started having lower back pain,and turned into swelling.I made an appt with my pcp for the following wk.at this time it had started bruising, she didnt know what to do and just gave me antibiotics.after 3 doses swelling bigger,warm to touch, causing fevers, umcomfortable,i went to er. Er said seek att from ps,got in following wk.Ps drained what ended up being 85 ml.next day it was swollen again,warm to touch.Should i keep getting it drained or do i need more surgery?