You may very well have to put cardio on hold for a week or two. Bear in mind, anything where you're feeling pain when you do the motion, you have to stop, you'll just make the injury worse. I took a step bad one summer and did the same thing, basically was homebound for two weeks. You should have the ankle wrapped with an Ace bandage and can also take over the counter anti-inflammatories (ibuprofen, Aleve, Advil) if your GI tract can take it, it will probably help more than Tylenol.
Little FYI: There are three levels of sprains. Level one sprains are considered slight. The ligaments are stretched but the joint remains stable. Bruising is minimal and a person can still put weight on the injured area.
A level two sprain results in some tearing of the ligament. There is swelling and bruising in the area. The injury is painful and there is a loss of ability to use the joint because of pain and stiffness.
Level three sprains are when the ligament is totally torn or ruptured. A person can't put any weight on the joint and there is pronounced swelling and bruising.
Sounds like you might have a level II sprain, and you might want to consider seeing a doctor.