Boyfriend dumbed me out of nowhere :(?

[Dancer4life]

I've been dating this guy for a year. everything was going fine, till i woke up one morning to find that he has blocked me on facebook. so i made a new facebook to see what was wrong, and he called me names and said i was a bad person. i am almost literally the nicest person on earth and people are always mistreating me. this guy was my bestfriend and he was the last person i thought would do this to me. we talked about marriage and everything. he told me he was in love with me first.

after a few weeks he called me like everything was okay saying "i bet you didnt think i was ever gunna call huh?" saying he was going to come visit me. then i messaged him venting about the stress i was going through, then he started calling me a bad person again and i told him to not disrespect me like that anymore. then he blocked me again. then a week later he unblocked me and followed me on twitter but hasnt spoken to me. i literally begged him to not leave when he was leaving me.

Almost every person i didnt think would leave me or thought loved me family or not has disrespected me, mistreated me, and left me as if i was nothing. I have gone into the worst depression of my life, and have been on the verge of commiting suicide many times. This guy was my 2nd bf ever and i'm 20. i did so much for him. i feel like a piece of shit.
Why did he do this to me?
i asked him why he was ddoing it to me, he made it seem like i was the bad person. i've slept in the car with this man, i've done so much for him.
he showed me more love than anybody has ever shown me which is why it hurts soooo bad.