This is recoverable, but you're going to have to work hard. Bother people. Bother your teachers. Make sure you understand every assignment. Read ahead, do your work the day it's assigned.
Are you enjoying your calculus classes? Did you enjoy O-chem? I have a physics bachelors, and our classes had 12 hours of homework per class every week. If the subject matter isn't interesting to you on a basic level, you're going to struggle. It only gets harder once you get to your real classes.
I will advise you to switch over the chemical engineering instead of chemistry, if you decide to continue to pursue this path.
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"What if you just eat vegetarians?"-neonreaper
"^ You are what you eat. ^_~"-Koiji