No one is asking you to be perfect.
Between school, work, organizations, a social life, and time to study, you need to remember to breathe. You need to remember that, yes, all of these things are important, but your health and happiness are very important as well. While school is the number one priority, it's OK to allow yourself to have fun sometimes.
And if one thing becomes too much it's OK to cut back. It's OK to not work as much or to tell your friends that you need time to yourself every once in a while. No matter how flustered you get with school though just remind yourself that it will all pay off in the end and before you know it you'll have your degree and then you'll be moving onto your career. Don't wish your time away because after college you're moving onto the "real world." You'll be getting a big girl or boy job and then you'll realize that the stress of school is nothing compared to the stress in the career field. It's a vicious cycle, everyone just has to learn to deal with it and adjust to it.
You're not the first and you're not the last person to get stressed and feel as though you are drowning. To feel as though you have so much on your plate that sometimes you don't know what's easier, taking the bull by the horns or climbing into a 50-foot hole and not coming back out until winter break. You aren't the first nor the last person to feel that way. In fact, I'm sure majority of college students feel the same as you.
So while you're studying for that history final or working on that project, remember that you'll get through anything and everything. Breathe, find time for fun and self-care, and just take each day one at a time.
"You must tell yourself, 'No matter how hard it is, or how hard it gets, I'm going to make it.'"