Nobody has ever been nothing. We are all equally something and some of us are much luckier than others. I was less lucky than I am now for over a quarter of my life, which is something like three quarters of my adult life - I’m not lucky enough to be good at math - my point is, I’ve felt like “nothing” for more waking hours on this planet than I’ve felt like anything.
I’m as bad at giving advice to others as you are at passing that med school test. But believe me, that’s all that test is measuring: your ability to pass it. It is not measuring the type or quality of doctor you might one day be, and it is certainly not measuring your worth as a person. If this is something you honestly want, I would bet you’re going to end up getting it. Or, at the very least, being totally satisfied that you left no stone unturned.
Your Mom is probably just expressing, in that frequently frustrating Mom way, that she’s worried she’s not being a good Mom. She doesn’t want to see you fail, she doesn’t want you to have a bad life, because she’s measuring her abilities as a Mom by your outcomes, same as you’re measuring yourself by this med test. I’m sure being a Mom is harder than being a doctor but I’m also sure the entrance exam was easier. Moms can’t push a button and stop being Moms just because we’ve decided we’re grown up, and the things they say in an attempt to keep “raising” us can get under our skin. But the biggest favor you can do yourself and your Mom (and everyone else) is to be confident about what you want. To know why you want it. Then you have honesty on your side. Then anyone opposing you is opposing the truth, and that’s a bad side to be on in the long run.
I don’t know you, I don’t know you’ll be a perfect doctor, or a doctor at all. There are realities with which to contend. But because reality is inescapable, it’s important that we make a choice, in our heads, to counterbalance reality with things that defy it. Gravity is a reality, but humans fly. The language we’re exchanging, the fillings in our teeth, the pavement on the road outside, everywhere you look, for better or for worse, you’re going to see evidence that accepting reality is not a human’s tendency, and not what we’re good at, and not, in my speculation, what God or Natural Selection hired us to do. We’ve been hired, by this universe, to dream, to aspire, to make things that weren’t real real - and because that involves a lot of failure, we’re damn good at doing that, too.
Without the benefit of details, I say stay the course. I say keep failing. Fall flat on your face, feel every scrape, roll in the dirt and scream in frustration. Tell your mother you love her but the fact is, she either raised a doctor or she raised a girl that’s going to fail, spectacularly, at it, and in either case, she’s done her part. Go fail that test a fourth time. And get it on the fifth. Or sixth. Push this thing to the absolute limit, make them create a new law against your level of desire, make them arrest you for wanting to be a doctor, and when they let you out, run to fail the test again, so that when you’re slipping away from this reality, which could happen at any time, you’re not spending your last moments thinking anything but “well, I did my best.” Also, watch Rick and Morty on Adult Swim in December.