College equals stress, as any student will tell you. Most refer to it as burn out, or running on empty.
While away at college you probably pulled all nighters, didn't get adequate sleep, and ate pizza, and junk.
The body can only take so much, until it says, enough.
Take the time to rest, increase your intake of good whole foods, and replenish needed nutrients, as well as water intake. (probably been going on caffiene for a while right?) dehydration causes fatigue.
The best supplement for stress, and fatigue is the B complex vitamins. They supply needed energy, and the ability to utilize nutrients, and feed the body.https://hubpages.com/health/The-Benefits-of-the-B-...
They are a necessary co factor in utilizing tryptophan, and producing serotonin.
For depression increase tryptophan containing foods, such as turkey, dairy, nut butters, and whole grains. It can also be taken in supplement form.
St johns wart is also a good herbal supplement in the treatment of depression.http://www.amazon.com/Natures-Way-Johns-Wort-Capsu... Do not combine with tryptophan, or with any other anti depressant.
If the depression, and fatigue do not subside within a reasonable amount of time, a check up might be in order, as it can be a symptom of something else.
My guess is your just running on empty.