I'm sorry you are in so much pain. I would second Old_Before_My_Time and suggest calling your family doctor to ask for pain medicine. I had a large cyst last year and I know how painful they can be. Do you have an appointment to follow up? Are they monitoring or planning to remove it?
Welcome to the community. I am sorry you are in so much pain. So did they not give you a prescription for pain meds when you went to the ER? Do you have a primary care doctor or ob/gyn you can call? Being it is the weekend, you would have to go through their exchange but it may be worth a try if you are still in excruciating pain. I hope you get some relief soon!