I'm starting to believe that...God might have made a mistake making me.

I'm a medic student. And there are times where it gets tough...and I feel really useless. Couldn't do well in exams. Other friends could, and no matter how hard I study, I feel like it wasn't enough. I just feel like I'm at the bottom all the time. I get it, my purpose is to serve people through medicine. But...maybe God made a mistake making me. I feel useless everyday...I want to end everything..but I have that voice saying " Just don't give up" . Any verses from the Bible I could read that you guys can recommend? Any advices /bible verses would be great. God bless.