"Atlanta broke my heart" ... so says 6LACK, who tells TMZ Sports he's rooting for the Falcons in the NFL playoffs -- but he doesn't want his soul crushed again!
6LACK is from Atlanta and grew up a Falcons fan ... but says he's being guarded this time around because, "I think I've just been scarred."
It's not just the 28-3 situation from last year -- remember 1998? When the Falcons were on fire only to get crushed by the Broncos in Super Bowl 33?
Yeah, 6LACK still remembers, too.
But deep down, he's all dirty bird ... and even gives his team some advice going into Saturday's Wild Card Game.