It is legal to make one copy of anything copyrighted for personal use, but this assumes that the original from which you have copied is legitimately obtained. In other words, taking something fresh off the web is illegal, but making one copy of something you, or someone else own, is legal.
Since you knew it was wrong, you are culpable. Since it was so much, almost a habit, you should mention this in Confession, but you do not need to state the exact number, just that it was a lot.
You do not need to turn yourself into the authorities and you do not need to reveal yourself to the companies but you could buy copies of what you now own illegally.
Nevertheless, the priest will tell you what to do.
God bless, and don't worry.