It's addiction and the fight to stay clean. The drug betrays making you believe it'll make things better and degrades due to the action one takes to obtain the drug. The fact that it's so hard to stay clean is asinine and makes you second guess your will.
One should be happy to be free, but it's a fault that sobriety doesn't bring happiness.
The pain of withdrawal is overwhelming and the voices are internal...calling... Yelling for you to get on with using.
This is just my opinion and when I say "drug" I mean what ever you can't give up and has control. Be it alcohol, sex, anger, heroin, meth, theft,food, women, men whatever your vise may be.