How To Treat A Seroma On Hip Leading To Pain And Swelling?

In October I got into an accident at my job and I ended up pinching my hip in between two hard surfaces and it instantly formed a seroma. I didn t have my seroma drained until 5 weeks ago. I went into surgery 5 weeks ago to get it drained and my doctor ended up putting a drain tube in. This drain tube stayed in for 2 weeks because it kept draining. two weeks ago I went back to the surgery doctor because my incision was still draining and not healing, so he put a chemical on it because he said the skin had grown around the tube instead of growing from the inside out. The incision is only draining a little bit now, but my question now is, why does the area, where the seroma used to be, is extremely tinder to the touch? It has actually gotten swollen from it hurting bad. I thought maybe I was just getting feeling back into that area, but it has just gotten worse over the last couple of days and icing it doesn t work anymore. Can you tell me what this could be?