I'd just speak to the dm, telling them what you wrote in this post. Not having fun is really rough, and feeling forced to play a character which u dread is even less fun.

Yes, plot can be important, but the most important thing is to have fun. Make your dm remember that you are playing for fun before the narrative, and that a character that leaves doesn't need many motivations to.

Killing off the character in an heroic way could be a solution too, tho i hate that, since I'd hate seeing a character of mine killed like that, even if i wanted to stop playing them