My Sad Room Mate-Destiel

Dean, in high school, always had a girl by his side. And in College, it was exactly the same. He was surprised to even get into a college, honestly. He wasn't the smartest at all, but what he could do was write. None of his peers knew that, though. They'd think he's soft, and Dean, the "bad boy", couldn't let anyone think that. Only teachers, and those who accept him into the dumb college knew of his talent. It all came so easily to him, he perfectly planned every word he spilled onto the paper, and it was a shame no one could see it for themselves.
Castiel was always quiet. He never put himself out there. Never voiced his own opinion, never put himself into a crowd, never got in any sort of fight- in fact, most people in his high school cant even tell you what he sounds like. All he was worried about was the future. He was constantly on top of everything. School work, his job, his family, he always tried to keep his family happy. Castiel was just a plain old person. No special talents, not a wit, nothing but a big pile of cash his family was kindly keeping warm for him. But that meant nothing to him. Cas didn't want money, or a scholarship, or to even graduate, he just wanted happiness. When he was 14 Castiel was diagnosed with depression.
As the last two boys to be accepted into this college, Dean and Castiel were put together as roommates. Just the two of them, in an apartment-living college dorm. Usually, this size place would have 4-5 guys living inside, so the boys felt lucky to only have each other.
It starts off casual, small talk in the morning and night, but it soon got deeper than that. Castiel discovered feelings he's never had before, as did Dean. Their "friendship" was like no other. They were so close, it almost made Castiel happy. Then Castiel does the unforgivable, and Dean ends all they had in the blink of an eye. Which only causes Cas to end what he had in the blink of an eye. And with everything ending, why doesn't Dean end his worries too?