Woke up last night with a severe calf pain and today it has been painful to walk, and it feels/looks swollen and hard. what should i do ?

Go to urgent care or hospital emergency dept and get this examined with at the least a Veinous Ultrasound to exclude thrombophlebitis

One does not give a history, if any of trauma or activities that might have caused this pain. Also is One taking medications like BCP or Hormones that could predispose one to this. That said; pain, swollen and hard calf are urgent indications to go to the ER before a potential blood clot is thrown into the circulation.