try not to panic. there are many options that are still available depending on your chosen college or university, their entrance requirements, and by how much your grade was lower than expected. try to keep calm while you work through your options.
when you go to collect your results, chances are your teachers will be on hand to celebrate and offer advice. see if you can grab a few minutes with them to discuss your grade and what options they recommend for you to consider next. teachers can be not only a calm voice of reason, but can also help put things into perspective. getting a c instead of a b 