Some forms of magnesium can help with sleep. Magnesium threonate makes me tired but doesn’t have a rebound effect like melatonin where I jolt awake when it wears off. The only issue is its cost, though it’s worth it for me.

Dopamine seeking?

I knew some families with that behavior. They are rare, but extremely hurtful. Look into trauma therapy (and ask a therapist what makes them qualified for that, instead of taking their word). You may have developed some hidden coping mechanisms just to survive, and a (good) therapist can help you determine if those mechanisms help or hurt you.

Your brother’s behavior seems extremely uncommon, to say the least. I can’t imagine that behavior being tolerated in a (functional) work place.

I wish you the best.

Eat until you’re not hungry, not when you’re full. That may require eating more slowly. It will be an adjustment for sure.