I feel you, and I'm terribly sorry to hear that's how things are. I don't know much, and I'm most likely less intelligent than most people... But I think you really need to go over your feelings for your wife. Do you still love her? How long has this downward spiral been going on? Like you said, it feels like you're being used and through what you're telling us... You are. She knows she can keep you from leaving and so she does whenever you tell her you've had enough.

Now, I don't wanna tell you to get a divorce and fukouttathere, but I think you really need to figure out if you love her, how your broken marriage is affecting your kids. Might I ask, how old are they? Speaking of your kids, it's really, truly, great of you not to off yourself out of respect for your children. I've been (and is, a lot of the time) down there as well and I've contemplated suicide several times. But after having had a daughter I feel I could never do it... It's an easy way out that leaves your family and close ones in great pain. I hate admitting that, because the more I say it, the less I feel like offing myself. And that's something I truly want to do.

Do you love your wife? Then be hard on her for using you and falling right back into her addiction. Do everything you can to help her get her shit together. At this point you have to be firm and maybe even give her an ultimatum (and I'm not much for that kind of handling of situations) if she's not gonna get her shit together: you're gone. No exceptions, no talking you back into it, because you know it's gonna drop right back to where you started.

It's a fucked up situation... But you're the fighter here. You're making ends meet for both your wife and your kids. You're still breathing even though you wish you weren't, for your kids sake. She can't be that strong herself right now, seemingly (I don't know your wife so I don't want to make assumptions) she can't even get her shit together for your kids sake. Do. whatever. it. takes. Even if you realize you don't love her anymore... Your kids deserve a mother. More so, they deserve a mother who's not fucked up all the time. Try an intervention, try to make her see how her actions affect your marriage, your kids, where she might end up in the future if you -do- leave. I know all of it is so fucking hard... But if you're the one helping her through her shit every time... Who's gonna do it if you leave her? Make her see how much she needs to change, for her own sake, for your kids sake, and for your sake.

I'm not sure I should be giving anyone tips on how to handle their lives... But all of this is just my opinion on your situation.

Good luck, and stay strong.