A mix of someone acting like a douchebag and a dickhead. Therefore, a Dickbag. Meant as an insult, if someone takes it as a compliment, that means they're more fucked up in the brain.
"My ex is such a dickbag for cheating on me"
"that girl really needs to shut up an stop being such a dickbag."
"Why must our teacher be such a dickhead??"