To be honest your brain tricks you in to wanting it..so you having a bad week your brain is making it an excuse to get some, because it wants it. Its called emotional relapse.. you can also cause arguments with your partner as an excuse to go get some. Its about knowing when these triggers come and how to prepare for them. So if your feeling stressed. Go for a long walk. Or paint or listen to some music with headphones or meditate. I know its easier said than done.
But after emotional comes mental relapse, were you start to think about using and how good it feels or things to do with coke. And then its physical relaspe. Were you end up getting it.
If you change your mindset at emotional and mental. You wont get it. Emotional relapse is pretty mad because your not even thinking about coke.. it could just be road rage or something bothering you and you want to relax. But really.. its your brain tricking you in to getting coke.