Can't Sleep, Mind Racing: Need Advice

I've been restless the past 2 nights and I have no idea why. I haven't been taking my medicine at all and these 2 nights i even took melatonin to finally get me to sleep before 6am but it feels like the melatonin just wears off an hour or 2 in and I'm wide wake with only an hour of sleep. I'm constantly feeling like my mind is going stupidly fast whenever I need to be asleep and I remember when school was still in and I was still taking medicine if I got less than 6 hours or woke up in the wrong part of my sleep cycle I'd be sleepy and groggy as shit and now these past 2 nights I've gotten 2 hours last night and 1 hour this night and I've woken up wide awake. My body definitely doesn't have any energy buy my mind certainly does. Hell if I didn't take melatonin tonight I would've been awake 24 hours on only 2 hours of sleep. I really need to find a physical hobby or workout so I don't get screwed over when school is back in. sorry for the wall of text it's really just my state of mind rn.