I Am Constipated. I'm A Man, Age 53, Never Had

I am constipated. I'm a man, age 53, never had this problem before. I eat healthy. No drugs or alcohol. Have not had a bm in 4 days. I get the signal to go, but I sit down for 15 minutes and nothing but pain. It feels like it's ready but nothing. Furthermore, urine flow is now at an almost dead stop. Can you help me?