Yes... My undergrad's chem dept was brutal. If you did everything right on a page-long stoichiometry problem, but then you accidentally forgot to round your final answer into sig figs, the prof would give you 1 point out of 17 on that problem. I got a whopping 7% on my first quiz (average was 12%)-- I didn't even know it was possible to score that low. I eventually climbed up into the top 30% in the class and walked away with a D. When I asked the prof about it, he said that I should be grateful for my score and that I should drop pre-med. Gee, thanks.
I retook it at another prestigious institution. I didn't work nearly as hard and got an A in the class... And ironically, I learned a lot more in this "easier" class. Go figure.
Don't let difficult classes or harsh grading curves bring you down. It used to make me want to quit pre-med, but it's just part of the struggle. Just keep your eye on the prize, study wisely, join a study group, find a tutor, and don't be afraid to ask the prof for help. If you get a bad grade, you can always retake-- there are lots of affordable course opportunities out there. With persistence and hard work, you will achieve your goal. 🙂