Go easy on yourself. God sees you and he loves and cares for you. Casting your cares on him doesnt mean you forget them, but its like giving over an important task to a trusted employee. You know the work will get done because they are faithful. Now Gods obviously not an employee but his promises say to cast your cares on him for his yoke is easy and his burden is light. He fights on your behalf. Repent what you need to, thoughts and all, and get back at it. You are made righteous. He cares about the desires of your heart.