Insomniac, ADHD son and insanely exhausted mom. HELP,

Guys I’m literally writing this after having several meltdowns today from exhaustion. My 5 year old has severe ADHD. He does. Not. Sleep. I recently had him put on adderall which of course makes it so much worse. The doctor offered klonopin as well but I wanted to just try melatonin because the thought of a sedative freaks me out. Especially with the heart risks and him being so young. He usually woke up around 3:30-4:30am but on the medication he’s been waking up around 11pm and again at 2:30ish and he’s up after that. We melatonin him again at 11pm and cuddle him back to sleep. To add, we’ve tried everything additional I can personally think of. His room is spotless before bed so it doesn’t overstimulate him when he wakes up, lavender in a diffuser/humidifier, sound maker, no TV close to bedtime, etc. He’s also been wanting to wake up and eat. He ate an entire box of rice crispie treats the other night while we were asleep when he woke up. Yes, I know about the eating ordeal. We make sure he gets plenty of nutrients throughout the day despite his lack of hunger. We anticipate him waking up hungry and wanting to eat at night so tonight we have started leaving a bottle of water and a baggy of veggie straws and a granola bar. Have any other parents been through this?? He was waking me up literally every 15 minutes the past 3 nights. I finally locked an extra tall baby gate so he can’t wander and get into everything. I’m at such a loss. Like is this permanent? Does it get better? I feel like I have a newborn all over again. I’m in the masters program for Clinical Mental Health (ironically) and my brain can’t even function to make a cup of coffee, let alone do school and do daily tasks. My husband helps but it’s so bad.