Whatever you have done in your past, if you've accepted Christ, repented and are firm in your desire to follow Him, to walk in the Spirit, it all has been forgiven.
However, that does not mean that sometimes doubts do not assault us. I can't speak for everyone, but I know it happens to me and it has happened to brethren I know.
One day, when I was having doubts, I ran into this piece and have kept it since, as a reminder of the inmense grace of God!
I pray it will be of help to you.
“WAITING ON GOD”
With the Lord…a thousand years are like a day (2 Peter 3:8 - NIV)
If we hold fast, “Other foundation can no man lay than…Jesus Christ” and “I am justified freely by God’s grace,” still Satan urges, “But the tree is known by its fruits; have you the fruits of justification? Is that mind in you which was in Jesus Christ? Are you dead to sin and alive to righteousness?”
And then, comparing the small fruits we feel in our souls with the fullness of the promises, we shall be ready to conclude, “Surely God has not said that my sins are forgiven! Surely I have not received the remission of sins. What lot have I, among those who are sanctified?”
But bind this above your neck; write it upon your heart: “I am accepted before God by the righteousness which is of God by faith.” Admire more and more the free grace of God in so loving the world as to give His only begotten Son, that whoever believes in Him shall not perish but have everlasting life (see John 3:16). So shall the peace of God flow on an even stream, in spite of all those mountains of ungodliness. They shall become a plain in the day when the Lord comes to take full possession of your heart. The Lord is not lacking for time to accomplish the work that still needs to be done in your soul. And His time is the best time. Therefore, ask Him and trust in Him, for He cannot withhold from you anything that is good.
From: “How to Pray: The best of John Wesley on prayer” 2007 Barbour Publishing, Inc. Pp. 48