Watery brown liquid from nostril after wisdom teeth close to sinus cut out even after finishing antibiotics. What is happening ?

I had my wisdom teeth cut out last Friday and my upper tooth was close or into sinus. But they were removed and I was having bleeding from nostril for a couple days. After a few days no more blood but a watery brown liquid was coming out of nostril and it smelled and taste like something decaying. I went back to doc he put me on a higher antibiotic and claratin d 24. First day went great I felt clear headache free and energized and had no more liquid or smell. Today I felt like my sinus was back in same headache filled way it was before. While playing with my 5yr old I filled my cheeks with air. My nose started burning and the liquid came from nostril again with decaying smell. So I filled my cheeks with air again but blew more pressure and my sinus opened and I could feel this stuff bubbling in my face and go through my sinus and out my nostril in large quantity until it was just air coming out. This was watery light Brown liquid with black speckles in it. Can you tell me what's going on with me and how can I get rid of it.