What do you do when you feel like you are so overwhelmed you can't handle it?

It’s my first semester away from home at college. I came here not knowing anyone and am four hours from home, haven’t seen my family in a very long time, am having a really hard time adjusting/finding good friend, and to top it all off- I have five classes and a ridiculously hard/time intensive lab. I’m really behind and need to keep an awesome GPA to keep my scholarship. I’ve been pulling it off, but all I want to do is crawl in bed and say “Screw it” because doing this every day is quickly becoming too much. I feel like I have a million things to do but never have enough time to do them. (Sitting on here isn’t helping, I know…) What types of things overwhelm you in your life? How do you overcome them?