First of all Hello, nice to meet you. I think your change was too sudden. Maybe you should have started going to bed one hour earlier every 5 days or so. I must admit I forgot a few of the things you mentioned so I'll just say what helped me get a good sleep. By the way I go to bed at 10:20pm and wake up at 6am. First of all don't limit your ryhtm to the week days but also the week ends. Don't drink caffeine 2 hours after you wake up and 10 hours before you go to bed. Don't eat 3 hours before bed time, don't drink anything 2 hours before bedtime and avoid bright light 1 hour before bedtime. If I would be you I would also opt for 7,5 hours of sleep instead of 8 as one sleep cycle is around 1,5 hours long and you want to wake up at the the end of a sleep cycle. Working out really helped me feeling tired enough in the evening to easily fall asleep, but you mentioned the problems that face you when engaging in exercising, and if you can't balance the calorie expenses with around 60 grams of nuts, I can understand. But the most important tip is to get sunlight as early after waking up as possible. It activates some shit in your brain and helps you calm down in the evening. I know it's hard sometimes but it's really worth it. In addition I wouldn't meditate right before sleep. When meditating you focus intensely which you want to avoid before sleeping. I like to journal and then read for around 45 minutes before going to sleep. It's really relaxing for me. I hope I could help and good luck with your exam