You’ll fit right in with the rest of us sinners. Some things people do are horrible, but almost all sins can be repented of. Even the lowest, meanest people can gain forgiveness and strive to do better. Today is a new day. Resolve to do better each day.
The one sin that God doesn’t forgive now or ever is the sin of calling evil good, or good evil. ie. blaspheming against the Holy Spirit. See Mark 3:28-30, Matthew 12:31-32, and Luke 12:10. Basically it’s if you attribute miracles of God to the Devil, or relate evil things to God.
On Wikipedia, I found this: In Roman Catholic teaching there are six sins that blaspheme against the Holy Spirit. They are: 1. Despair (believing that one’s evil is beyond God’s forgiveness); 2. Presumption (glory without merit, that is, hope of salvation without keeping the Commandments, or expectation of pardon for sin without repentance); 3. Envying the goodness of another (sadness or repining at another’s growth in virtue and perfection); 4. Obstinacy in sin (willful persisting in wickedness, and running on from sin to sin, after sufficient instructions and admonition); 5. Final impenitence (to die without either confession or contrition for our sins), and 6. Impugning the known truth (to argue against known points of faith, and this includes misrepresenting parts or all of the Christian faith to make it seem undesirable). [1] [2] [3]