What just happened to me?
You were forgiven completely, made brand new, and adopted into God's family. 2 Corinthians 5:17 says the old life is gone - a new one has begun.
This wasn't self-improvement. God actually did something: your sins are forgiven (1 John 1:9), you're a new creation (2 Corinthians 5:17), you're God's child (John 1:12), and His Spirit now lives in you (Romans 8:11). You didn't just turn over a new leaf - you received a new life.
You may feel different, or you may not. Either way, it's real - because it rests on what Jesus did, not on what you feel.