Why would he have to repent of something he was asked?meant to do? If God selected him for that part of Christs mission. Judas should have been welcomed in to heaven and given a hearty well done.
I believe he “confessed” his sins to the Pharasees when he returned the silver By giving it back he was showing that he didn’t do it for money. He did it out of obedience to someone much higher than they.
As for committing suicide one account is he hung himself and another is that he “fell headlong into a field”.
One other point, Judas was the treasurer of the group. He would have been the one to take the money.
I also think Pilate got a back rap. He washed his hands of the whole affair. And by law he had to do what the Jews wanted.