The other posters have some great points. Only you can determine when it would be wise to seek some extra assistance (from the student health ctr, etc). You sound like a smart person.
Having said that, there are always things you can do to make things better (or worse).
And that's empowering.
Don't let yourself wallow in isolation. Getting outside, taking a walk, doing something nice for someone else, taking a class in something just for fun (an art, cooking or exercise class, etc) can help to get you "out of your head," if you know what I mean. Perhaps volunteer somewhere to help at an event. The surest way to have a friend is to be a friend. The possibilities are endless.
Can you get in touch w/ any of your former friends? There's no shame in admitting that you made a mistake in excluding them from your life. You certainly aren't the first girl to do that. Men may come & go, but good friends are forever (or can be). They may be happy to hear from you. There's a saying: Sorrow never leaves you where it found you. You are learning from this and other things ever day. What never fails to help me when I've been down is to take pen to paper and write out all the things I'm grateful for, even if they sound mundane (one time my list included street lights, of all things!).
Lastly, you are young and break ups are part of living and growing and learning...about the other person but also about you. As you grow through this, be kind to yourself. Do at least one good for you thing a day - whether that's drinking your water, eating more veggies, putting on some good tunes and dancing your face off, getting enough sleep, etc. If you start taking better care of yourself mentally & physically, you might find you have more energy.
I hope you are feeling better w/ each passing day. And this is the perfect place to post if you need a little friendly encouragement from your fellow Sparkers. Promise you'll seek additional help if you need it. In the meantime, get busy w/ doing some or all of the above.