Just an idea, if your psychiatrist is willing and nothing else is working (organization coach etc), Wellbutrin might be something to try. It's used off label for ADD/ADHD and while it's not as effective as stimulants it works for some people. It's also a dopamine agonist so it increases the amount of dopamine in the "reward centers" in your brain and may help with your comfort eating. People often lose weight on it, it also has a mild appetite suppressing effect.

Your parents and psychiatrist will likely be much more willing to try this than stimulants, many psych docs are reluctant to prescribe stimulants. Strattera would be another option. I works a little differently, so it likely wouldn't have any effect on your eating habits.

Just something to think about.

Oh, by the way, you can buy melatonin almost anywhere. Even grocery stores, Wal-Mart and Target carry it.

Good luck.