Feeling sorry for one' sins is the only right starting point, but for true forgiveness, one needs true repentance, it has to be in light of God's standard of right vs. wrong.
It's not enough to simply be sorry because you missed up, it needs to progress to an understanding of "I've wronged God."
How can you be released from a debt, even an eternal debt, if you don't believe that you owe it?
Amen to that.
And to Calvary John: I apologize to you if my words appeared to be anything resembling a slap at you. That was not my intention.