Gonna have this for a while and it's gonna be tough to deal with, no point pretending otherwise. Good intentions and will power fade with the memory of how bad detox was or how much life sucked in days gone past that led you to detox in the first place, the good times become romanticised through rose-tinted specs and a lowering of tolerance that might have killed the good stuff so completely you've been using just to feel normal after long use renews their appeal. It can be done as a pure effort of will if you can sustain it while the cravings die away but can take a while, some need help to keep the motivation going. NA or something similar as group therapy / support structure could be very useful for you, worth giving it a try at least even if it doesn't agree with you in the end. Could be of use just long enough whatever happens, what you got to lose?
The key thing with cravings is not to dwell on them, otherwise you get into battling with yourself about whether you're gonna give in to them or not so they become kinda self-sustaining, really winds you up. Recognise them for what they are, acknowledge them but assert your control with a no, I'm stronger than this and do not not have to act on these cravings at their insistence. The more you do that the better you get at it, the easier it gets to dismiss them so they don't linger on so much and time heals most things if left to its own devices too. They will pass and you can cope with them if you want to. Failure will be because you want to fail. Going backwards will be a decision you actively make for yourself in the end, cravings or no. Make an active choice not to do that.
Best of luck.