I Had A Burst Cyst Next To My Spine Several

I had a burst cyst next to my spine several years ago (13yrs?) that was drained with a scalpal after it filled most of my back with fluid and puss. After weeks of compresses and expressing it eventually healed. Last few months it had begun to grow slightly leading me to believe it had come back. Today it spurt out cottage cheese like puss, about 1/3 of a cup, with a deadly stench. I have expressed as much as I can alone but can’t see or reach as well as a second pair of hands would. Any thoughts why it recently filled and began to overflow?