Whenever I sin, I doubt!  And I know that's crazy, and I know and I realize how self absorbed I am, so it's not going to hurt when you tell me that!  But I think within the last couple of weeks I have understood a little more about what it means to trust in Christ alone for salvation.  I know that I can do nothing to please God or make me right with Him.  I know it is through Christ alone and His righteousness is what makes me right with God, not my own because mine are nothing but filthy rags, yet I still doubt because I believe I equate my salvation with my performance, but I don't know how to get out of this "rut"?

"ROM 7:15-8:1  "...what I am doing, I do not understand. For what I will to do, that I do not practice; but what I hate, that I do. If, then, I do what I will not to do, I agree with the law that it is good. But now, it is no longer I who do it, but sin that dwells in me. For I know that in me (that is, in my flesh) nothing good dwells; for to will is present with me, but how to perform what is good I do not find. For the good that I will to do, I do not do; but the evil I will not to do, that I practice. Now if I do what I will not to do, it is no longer I who do it, but sin that dwells in me. I find then a law, that evil is present with me, the one who wills to do good. For I delight in the law of God according to the inward man. But I see another law in my members, warring against the law of my mind, and bringing me into captivity to the law of sin which is in my members. O wretched man that I am! Who will deliver me from this body of death? I thank God -- through Jesus Christ our Lord! So then, with the mind I myself serve the law of God, but with the flesh the law of sin. There is therefore now no condemnation to those who are in Christ Jesus, who do not walk according to the flesh, but according to the Spirit."

But doubt is another thing to contend with.  We are to make every effort to be as holy as God is holy, but yet we will "always" fall short, but we should see some growth in holiness each year as we grow in our walk with the Lord.  The good news is that the Lord looks at our hearts, and what He wants to see is a "commitment" to walk holy and "strive" to be obedient, and make serious efforts when we do sin, not to do it again.

We are like little children...when we watch our toddlers try to do good, but fail because they are still learning how to obey, we are gentle with them, because we know they are trying.  But as they grow and sometimes become stubborn and refuse to submit then we have to take a more active part in the process.

You sound like a very normal Christian who struggles with sin, and your conviction and hatred of your sin is very convincing that you are truly saved.  Remember, Satan and the evil ones are always trying to rob us of "the joy of our salvation," so when we sin and sin, we just need to stop and repent and receive the sweet forgiveness from our lovely Lord, who has not only paid for all those sins, but who is engaged to be married to us in the future, and then we will be His bride for all eternity.