For some people, life is composed of destructive cycles of self-loathing, comforting behaviour, self-assurance, self-disappointment, and further self-loathing. Often this comes in basic addictions such as alcoholism, excessive gambling, pornography, or addictive substances. The thing is, these cycles can often be fairly mild, even to the point of reasonable acceptance, such as in the case of many nicotine addictions. Some smokers don't really hate smoking all that much, they've just realised that
hating smoking is what it will take to quit. Perhaps smoking is the special exception where the degenerative cycle is commonly harnessed as a source of motivation for finding an exit from the unhealthy pattern. It's a clever and effective tool of self-improvement which begins with recognising the problem and the recognising the power within one's self to effect a new, more satisfying pattern of behaviour (maybe take up sunflower seeds?)
For some people, this kind of destructive pattern takes a bizarre form: addiction to incompatible people. Now, why does this happen!? How many of us know at least one person who has been dating the same asshole retard on-and-off for eternity, against recommendations of friends and loved ones, blind to what they really are: a bad influence. This addict can't recognise the negative cycle they are caught in because there are often moments of positive reinforcement which escalate the cycle enough to continue through another bout of loathing and depression. It's a lot like when a gambler hits a big payout at the slots. It's a rush, an assurance, a feeling of being okay after all, even though the power is scheduled for disconnection at home. It's enough to get through that period of sitting around in the dark, hating your circumstances, hating yourself, even. Eventually, you take out another loan to pay off the power company, get things back on track (sort of) and move forward. The thing is, by then, you're building up a history of patch-fixes which take more work to undo than planning ahead would have.
People in destructive relationships are equal participants with their partners in an addictive cycle much like the one described above. You fight and fight until you hate each other and yourselves for getting involved, but eventually you latch on to that feeling that "maybe I can make this work, and things will be okay." Jackpot! You've got a patch-fix (such as ignoring an issue) which builds up over time with every other problem that doesn't really go away and all the while you've convinced yourself that things are looking up and it was all worthwhile. Meanwhile, the power is scheduled to be disconnected at home, only this time, I'm talking about emotions.
If you find yourself in one of these situations, do your future self a favour and see it for what it is. Depression leads to some very irrational thought which always
seems perfectly appropriate at the time. Recognise this now and don't put yourself in such a vulnerable state of mind. You wouldn't drink 20 shots of vodka before going into court to defend your best friend on a false murder charge, so why would you stay in a relationship that has put you through depression more than once?
Separate yourself from the junkies, gamblers, and alcoholics. Keep your head straight. Above all, don't put yourself in denial, no matter how much more comfortable it is. It's the loser's way out, and it's the reason we have 50-year-old losers out there--I know you've all seen them.