"When Christ's faithful strive to confess all the sins that they can remember, they undoubtedly place all of them before the divine mercy for pardon. But those who fail to do so and *knowingly *withhold some, place nothing before the divine goodness for remission through the mediation of the preist, 'for if the sick person is too ashamed to show his wound to the doctor, the medicine cannot heal what it doesnot know'" (CCC 1456) (Italics mine)
You knowingly confessed everything you could think of. You knowingly told the number as best you could. Therefore, everything is absolved. To think otherwise is to allow Satan to steal the peace God gives through the sacrament.
In regard to Mortal sin: 1) Is sin whose object is grave matter
2) Is also committed with full knowledge
3) And deliberate consent.
In other words, It has to be grave (against the 10 Commandments), you have to know it's grave, and then you have to do it anyway. If you are unsure if you committed a mortal sin, you didn't.
It may be a grave sin. It may be a serious sin. But it's not a mortal *sin unless you *knew it was before you did it, then you did it anyway.
For example, an unchurched 16-year-old girl is forced by her parents to have an abortion. Neither the girl, nor her parents committed a mortal sin because neither the girl nor her parents knew abortion was wrong at the time.
Also, because you made a good confession, no, you don't need to confess anything you forgot. That's what the Catechism says above. If you feel you want to, or need to, for your own peace of mind, then go ahead. From God's perspective, when sin is absolved, it ceases to exist. You don't need to confess something that doesn't exist any more. From a Catechetical perspective, and a sacramental perspective, you don't need to. That's not my humble opinion. That's from my priest/confessor. It's what he told me when I discovered I was supposed to have made a general confession when I came into the church covering my life from the time of my baptism at age 12 to my first confession at age 42. I did not know that, so had never done that. But while it's pretty safe to say some of the things I did back in the day were mortal sin, because I had since made a good confession, I did not need to go back and confess every stupid thing I did when I was 20. Or 21. Or 22. Or...:shrug: