No place in the New Testament does it teach that Christians cannot approach God themselves but must have someone else to intercede with God on their behalf. It is definitely helpful and encouraging to have others praying to God for us (cf. James 5:16; 1 Tim. 2:1), but that does not preclude our own right and ability to go to God directly ourselves.
Underline the word “you” in this statement from Jesus, “Therefore I say to you, whatever things you ask when you pray, believe that you receive them, and you will have them” (Mark 11:24). Oh, what a blessing! You can pray to God! You can ask God in your own prayers! And, you will be blessed! I need others to pray for me; I want others to pray for me! The apostle Paul is a great example of that (asking brethren to pray for him, cf. 1 Thess. 5:25). However, a great privilege of being a child of God is talking directly to God! What a thought!
When you need forgiveness, you need to pray for it. Jesus gave you that right!