God in His foresight has already forgiven you of all of your sins (Colossians 2:13). Jesus made it to where you cannot damage your standing or relationship with Him on His side.
God does not count sins against you (2 Corinthians 5:19). So He doesn't want you to live as though He does. Because He is not counting sins against you it is not good for you to count things against yourself. God wants us to come to Him with our struggles but He also knows that focusing on past destructive actions does not better us. I used to go and confess lusts and it would bring the lusts back into my head and body. It is better for us not to be conscious of sin (Hebrews 10:1-2). We're told in Romans 6:11 to consider ourselves dead to sin. Why? Because we are. We are dead to sin (Romans 6:2). Dead men don't react, confess, or turn. God doesn't want us to live a lie or to pretend. He wants us to join Him in reality and what a wonderful reality He has provided for us in Jesus!
Our relationship with God is superior to our relationships with others because God is perfectly & selflessly loving. He never gets offended or angry because He put that on Jesus when He condemned sin in His body. God cares for our well-being so much that at the cross He removed anything that could possibly stand between Him and us. His forgiveness is already completed and we get to enjoy that reality all the time when we recognize it is complete. If we don't recognize His complete forgiveness then asking Him for forgiveness allows us to experience His forgiveness. Asking God for forgiveness doesn't gain new forgiveness, God doesn't have to forgive us again anymore than He has to be crucified again. Asking God for forgiveness just taps into what has been there since Jesus rose again.
It is great to have an open, honest relationship with God but it becomes even more wonderful when we live in the truth of what Jesus has done for us.