They usually will leave when the raid ends, but this is a gradual thing as they wander around and aggro other things. Problem you're experiencing is that they're aggro'd to your bed, and maybe a few other base items. So, they kill you, then in the time between you dying and the game de-rendering them, they stick around to attack your bed, then you respawn, then they kill you, and so on.

Eventually, they'll break everything and go away, but it might be worth it to load into the world with a different character to give them a few moments to do their thing if you just want them to leave. Cap'in Bells advice is pretty good too; get out of the cycle, build up your strength somewhere else, and come back for vengeance.

Going forward, use this experience to help you figure out how to design a defensible game; base building is a large part of this game.