Pulled a muscle or torn ligament whilst running, heard snapping sound from my calve. what can it be? hurts lie?

Sounds like you ruptured the gastroc solius muscle. You need to get a cast or aircast walking boot to prevent you from moving your foot and ankle up and down. You might want to get some crutches initially until it feels comfortable to walk on. It takes about six weeks to heal. See an orthopaedic sports medicine doctor