Being a Dishonest Cheat. How do I live with this?
It seems that you already know what to do. You said it yourself, you've struggled with engineering since you started and you had to cheat on an exam that is a pre-req for your future courses. Classes aren't going to get easier and you would be wasting your time and money pursuing this degree. Is there a reason why you're still in engineering? Is there anything personal keeping you in this curriculum? Re-evaluate where you want your life to head.