Friend, this is a recipe for despair. I know, because I walked for many years in your shoes. I admire you for continuing to cleave to God even through your belief that your salvation is a fleeting temporal thing. For my part, I gave up trying to be perfect and walked many years in spriritual darkness. Then one day the Lord allowed me to understand that Christ does not lose his sheep, and my salvation finally filled me with joy, rather than fear.
For theose in Christ, there is no condemnation. We will be judged for our works there is no doubt, and many believers will escape damnation "only as one who passes through flames". But Christ will bring all of His sheep into the fold.
I am reminded of the illustration of a criminal before a judge. His case has fallen to pieces, and he knows that he is guilty, and that the penalty is more than he can bear. The judge reads the verdict: guilty on all charges. The gavel bangs. Then the judge pronounces, "You deserve a strong sentence for what you have done. Indeed, you can never make restitution for your crimes, even if you live forever. But because I Am merciful, I will serve your sentence for you. Out of my great wealth I will make restitution for your crimes. And you will be my adopted son and live in my house all of your days." Then the judge removes the prisoner's shackles and leads him out of the courtroom.
You, my friend, are the criminal, and Christ is the Judge. Yes, you are guilty. But He has paid your penalty.
But Christ will bring all of His sheep into the fold.
Christ doesn't lose His sheep, I agree. But what if the sheep lose Him? What if a sheep deliberately wants to wander off and fall down a cliff? What if the sheep no longer wants to be a sheep, and now wants to be a wolf instead? If a sheep is bound and determined to turn his back on the Shepherd and leave the fold and never desires nor seeks to return, then the sheep will not be part of the Kingdom.