Honestly, I completely agree that using drugs for self preservation is better than suicide, but you need to weigh which option is better in the long run. An addiction that starts to drain your life, or suicide. For some, having that life being drained is better than no life at all, but addiction is just a slower death.
The willpower of people on this site is great though, I honestly believe the grand majority know how to combat addiction and be able to use drugs to get them through tougher periods as a mood elevator. I'm having to do it myself and it's hard, but on your better days you'll be happy you didn't die. Life's about the good days, right?