Alright, I'll go against the grain and say "Talk it out." But, leave "Throw in the towel" as an option. GalaGirl spoke of a three-strikes rule. I sometimes advocate something similar, only it is a "one-year rule." Doesn't have to be a year, could be a few months or something, but pick an amount of time that's the longest you think you can hack the current dysfunction in your relationship. Then tell your partners, "I need to feel like there's *some* kind of improvement by [such-and-such] a date. If there isn't, then I need to break it off (or at least take a break from it for awhile)."
I think the reason there are so many "Throw in the towel" votes is because people are concerned about your well-being, and want to encourage *you* to take care of *you.* Don't put up with unreasonable behavior. Decide what you (in your mind) perceive as rational limits, and what counts as evidence that someone is at least trying to do better. What do *you* need in order to feel like there's hope? Communicate that to your partners, and make sure it happens within some kind of reasonable time frame.
So talk it out first, but be prepared to throw in the towel if it comes to that. If you do end up throwing in the towel, by the way, do it amicably if you can.
I hope things work out.
Love means never having to say, "Put down that meat cleaver!"