Trying to understand my withstanding emotions?

[Starplayer421]

m a 20 year old woman in college (dorming). I spent a month and a half spending a lot of time with a guy, last year (fall of 2014). We cuddled, made out, I stayed over in his bed 7 times and we texted daily. He would invite me every night to come and hang. We told eachother we liked eachother. Some crazy drinking went down on my birthday in October (2014) and I ended up in the hospital for a week (the drinking just made it all surface - there were problems previously though ). Due to severe depression and suicidal thoughts- which I continued to recover from even after release( meds take up to two months to work). Basically he dropped seeing me or even speaking to me except for one time after I came back to school. I told him how he played me and that I wanted to understand why he was acting this way. He often ignored my messages and I cried a lot over everything. Even to this day we don't talk or even acknowledge eachother/ blocked eachother on social media. we were never official and he was always weird about that. For some reason still seeing him around campus makes me feel sad and a bit broken up inside. I've dated people since those incidents (official and unofficial) but how can I still care about him a year later? He's still the person I'll drunk cry about, but I know he's not a kind person.