Addiction is a disorder that is still being constantly studied and puzzled over by top neuroscientists. There are even not one, but multiple models with which to understand addiction! So you shouldn’t feel bad ab out not understanding your addiction. It is important to understand that it is complex, multi-faceted, and will take multiple approaches and trial-and-error. Relapsing even is a common part of addiction recovery and not a moral failure.
Talk to your doctor and see if supplements may be part of a addiction recovery regiment.
Warning: take extreme caution when combining medications/supplements that increase serotonin as there may be a risk of serotonin syndrome.