I would drop out and retake your A-Levels. Try the open university.
Basically if you are struggling so much, your final grade wont be enough to get you a good job anyway. Regardless of how much getting caught will RUIN your life.
Personally i would drop out now, fix your a-levels and go back to uni when you have the knowledge. Or at least enrol in online a-levels and actually DO the work.
Would you be happy if you knew you were relying on someone like you in times of desperation for legal aid? I think not. You could really mess up people's lives.
Please have the courage to stop this now and fix what you are doing before you either get caught and get into serious trouble and can't go back... or somehow manage to scrape by and ruin other people's lives in the future.
Do the right thing. This is not ok. Not at all. Don't let the rest of your life be a lie that you didn't earn or deserve. You can fix it now before it's too late.