James, Peter, John, nor Jude make any mention of Timothy in their letters, while virtually all of Paul's letters make mention of him (Romans, 1st and 2nd Corinthians, Philipians, Colossians, 1st and 2nd Thessalonians, 1st and 2nd Timothy, Philemon, and, of course, Hebrews).
It was pretty obvious Timothy was brought into the fold through Paul. The only other book in the New Testament that mentions Timothy is the Book of Acts, which references most integral people in the early church.
So... I would again suggest that Hebrews was indeed written by Paul.
How to repent:
2Chr 7:14 if my people who are called by my name humble themselves, and pray and seek my face and turn from their wicked ways, then I will hear from heaven and will forgive their sin and heal their land.
Step 1: Humble yourself by recognizing life must be lived God's way, not our way.
Step 2: Pray and seek My face.
Step 3: Turn from your wicked ways. Repentance is easy if you've done the first two steps. Thank You, Jesus!