Hi again ((((((((Steppalee))))))))) (I responded to another one of your posts earlier)
You can do this, you might have difficulty stopping by yourself - but I know if you ask for help from (good) reliable friends, they'd be willing to help. If not that, have you ever gone to an NA (Narcotics Anonymous) group? There would probably be a lot of support there - people who would totally understand and could help you through more than people on the other side of computer screen.
You haven't failed. You won't fail. You *could* fall, but I think you won't because you've recognized the thought patterns and now realize that you can stop things before they start - just because you think about doing something, doesn't mean you *have* to do it. Do you have a therapist or someone else to talk to?