I was caught cheating my biology class, the teacher wants to talk and I don't know what to say?

Every week in biology we are assigned about 300-400 multiple choice questions. They are on a website, the server is run by Moodle, and each practice exam we do has about 50-90 questions and we do four. However, along with a few other people, I photoshopped the quizzes and printed them out to submit. I studied the notes and I listened in class, I just didn't have any time to complete the assignment. Every week, twice a week (Saturday and Sunday), I have to go to work for about 4-5 hours. We have time during the week, but I'm constantly doing geometry, history, Spanish, English, etc. It's hard to leave time for these exams, each one takes about an hour to an hour and a half. So, I thought it would be easier to cheat, but cheaters never win and I have to see him tomorrow (along with a few friends) to talk about the situation. Unlike my friends, though, I've photoshopped every single exam for the whole year, besides a few every now and then. I don't know how I'm going to explain this to him, and I know I'm going to own up to what I did, but I don't want a harsh punishment. How can I make this load seem a little less... bad? How do I sugarcoat the number of practice exams I cheated on (keep in mind, he has access to these so I can't blatantly lie). It would mean a lot if I could get some tips and skills about talking with a teacher, and also how to negotiate (in sorts).