Why can't I sleep like I used to sleep before?

3 years back I used to sleep like a dead body 🙂 but now it's been around 3 years I sleep late and even when sleep I m around 40% aware what's happening around me and when have little sleep I have many vivid dreams like blood shed people crying and I m just trying to help them ...and just normal thoughts in head keep striking like fan is moving, I drove bike fast it was nice turn .. just random and simple thoughts. About lifestyle I don't exercise at all already left gym sometimes back. Sleeps late. Wake up late because If I sleep at 2 or 3 then waking up at 9 will still feel dizzy, so wake up at 11 and start my day. And having few bad habits too. 😂 Yeah I can see what I need to work on but my brain is tricking me asking for assurance that it will be better if i work on above issues. Don't know how to start how to plan how long it will take. 😂😂😂