Two Days Ago, I Had A Coughing Episode When Water

Two days ago, I had a coughing episode when water went down the wrong passage. The choking and coughing spell was quite brutal, but I eventually cleared my airways. The next day, I noticed pain in the muscle located above my anus opening. The pain is progressively getting worse. I've taken muscle relaxers and have showered in very hot water three times a day. This offers some relief, but I can barely sit for any length of time. Did I strain this muscle coughing? If so, how can I relieve this pain?