Doesn't Judas' regret count for something when God judges him?
The original Greek wording helps to understand what was happening in these verses. The study note for Matthew 27:3 shares the following:
felt remorse: While the Greek word me·ta·meʹlo·mai used here can have positive connotations (rendered “feel regret” or “regret” at Mt 21:29, 32; 2Co 7:8), there is no indication that Judas was truly repentant. When referring to repentance before God, the Bible uses a different term, me·ta·no·eʹo (rendered “repent” at Mt 3:2; 4:17; Lu 15:7; Ac 3:19), which signifies a strong change in thinking, attitude, or purpose. Judas’ actions of returning to the very men he had conspired with and then committing suicide show that his thinking remained distorted, not changed for the better.
The topic "Repentance" from the Insight on the Scriptures gives additional wisdom:
Judas, after having betrayed Jesus, “felt remorse [form of me·ta·meʹlo·mai],” tried to return the bribe he had bargained for, and thereafter committed suicide by hanging. (Mt 27:3-5) The enormity of his crime and, likely, the awful certainty of divine judgment against him evidently overwhelmed him. (Compare Heb 10:26, 27, 31; Jas 2:19.) He felt the remorse of guilt, despair, even desperation, but there is nothing to show he expressed the godly sadness that leads to repentance (me·taʹnoi·a). He sought out, not God, but the Jewish leaders to confess his sin to them, returning the money evidently with the mistaken idea that he could thereby to some extent undo his crime. (Compare Jas 5:3, 4; Eze 7:19.) To the crime of treason and contributing to the death of an innocent man, he added that of self-murder. His course is in contrast with that of Peter, whose bitter weeping after having denied his Lord was due to heartfelt repentance, which led to his being restored.—Mt 26:75; compare Lu 22:31, 32.
So while Judas may have felt bad about what he had done, his actions did not show that he had true repentance towards Jehovah God.
[All scripture quotations from the New World Translation of the Holy Scriptures (Study Edition)]