I work nights and average 4 hours sleep split between 2 naps. Where there’s a will, there IS a way. I find fasting actually boosts my energy so I naturally reduce my caffeine intake. I am on Day 3 and energy for days! I’m here for you!
Vigilance pays dividends. Cut caffeine. Cut exercise in the evening. Cut screen time in the evening. Wake up at the same time every day no matter how tired you are. Use light screens in the morning. Consider supplementing melatonin at night. Eventually your circadian rythm will reset and your sleep will return to normal. It took me months, but it does happen eventually. Probably depends on how messed up your sleep was to begin with. It’s also worth noting that some sleep problems are caused by disease (sleep apnea) and seeing your doctor to rule out anything medical would be step number one.