Once Jesus is handed over to Pilate, Judas tells the Sanhedrin that he was wrong. You can read about it here. Judas offers to return the 30 pieces of silver, saying "I have sinned by betraying innocent blood". Scripture says that Judas was "full of remorse". Wow. Just wow. I can't even begin to understand the hopelessness Judas must have felt when the Chief priests and elders dismissed him.
None of us do.