If I got a quarter every time I said "I'm stressed," I could cover the cost of my university's tuition. I could probably pay off yours, too. To put it simply, school has always been stressful for me. What I've learned to do is channel that stress and use it as a tool to reach my goals.
While many factors of stress are out of your control, there are plenty that you change. The key is finding which ones those are. If you are overwhelmed by keeping track of all the classes and clubs you need to attend, try writing out your weekly schedule and adding extras in something like an agenda. If you are like me and find that hard to keep up with, try something like your phone's calendar app that can give you notifications of where you have to be and when. Everyone knows that being organized is important, but not everyone realizes that there are so many different ways to do so. Figure out what works best for you.
Grades are another huge stresser in school- probably the main one for many. Aside from the obvious tips like working ahead and getting sleep, I find it helpful to remember that you're not the only one stressed out about that upcoming final exam or big presentation that you have to give. Reach out to other students in your classes, even if you normally wouldn't. It can help to hear their thoughts. If you can work together on homework or studying, you'll be exposed to much extra shared knowledge. Even more importantly, you'll find someone who knows the struggle you're going through.
For me, stress is usually a source of motivation to work hard and get things done. Sometimes, though, it is important to take a step back and evaluate whether the cause of overwhelming stress is worth it. Your health is always the most important. If you don't know how to alleviate the pressure and it becomes too much, don't be afraid to reach out for help. Talk to counselors, advisors, and professors so that they can lead you on a better path. If something like a certain class or activity is taking its toll, sometimes the true sign of success is knowing when to back out for your own good.
Stress is inevitable every now and then, but with a smart approach, you won't let it get the best of you.