I need advice. 

I’m getting close to my thirties. Some college credits. Full time job that’s physically demanding. 

In high school to present day, I would generally sleep 10-12 hours a night, go to school or work or both for 8+ hours and have 0 to a few hours of awake time for eating; errands; adulting; workout or studying/homework. I could never, for the life of me, manage my time in a way that I got enough sleep and successfully achieve everyday life. 

I’m talking 40-50 hours working a week; sometimes 60 hours with two jobs. 
15 hours of school and studying a week for college. 
I physical cannot function with 7-8 hours of sleep if I work 8 plus hours. Why? I HAVE NO IDEA! I’ve tried and tried but I cannot do it. I either sleep 9-12 hours or wake up and be groggy all week. 

So that left me literally waking up, work, school, then sleep. All until my day off. 

Is there any chance to be able to train myself to be more productive and handle 7-8 hours of sleep? Am I just doomed and will forever need 9-12 hours of sleep? My performance work diminishes if I don’t sleep a lot. 

I was unemployed for almost two years of my life and I was then able to sleep 7-8 hours and be perfectly fine through the day.

I really want to go back to college and finish my credits as full time student and full time worker. Along with hobbies and side business. Any advice as to stretch myself in a way that I won’t fall into a depressed hole? How do I know when to call it quits and focus on my mental health instead?

I drank a ton a coffee in my early 20’s. Now it makes me extremely sleepy and lots of anxiety. I’m better off with the unhealthy energy drinks. But even then I rather stay away from those. 

Is this normal?