Welcome to Gaia! ::

It's expected.
The only advice I can give is that you stop that sleep habit immediately by not sleeping. I understand school is exhausting, believe me. I know. My senior year starting off was really s**t tacular.
To briefly explain all that, my Grandma had a heart attack over summer break. My Mom went to her place on the other side of the state to take care of her for two months, which went over into school time for about two-three weeks. While this was going on, my Dad worked every day until he practically collapsed. This meant I not only had major Senior school responsibilities, but all of the house responsibilities too. And I live on a ranch, so there's more responsibilities to do here than in an average house. I even went through a night with no sleep because my Dad screamed at me about the dog getting sprayed by a skunk, and he locked her outside and I was too afraid to bring her back in even after a couple of hours. But she wanted in, so she barked outside my window all night long and kept me away. I seriously think I got a total of two hours of sleep. And this was during that time where I'm doing everything around the house and all my s**t at school. So believe me, I wanted to ******** die at the end too.
To make matters worse, my parents returned to her place several times throughout fall and winter. There was a time they were there for five whole weeks. When it was just my Mom, I still had Dad to fall back on when I could. But for five weeks I was on my own for a huge a** list of chores and school. It was the worst time of my life because I was extremely stressed out with no way to really de-stress and relax.

But you can't do that. You need to work a proper sleep schedule, and the first way to do that is to not nap immediately after school. Unless you are getting at least eight hours prior to school, naps usually ******** up when you go to bed. You're not so tired, so you stay up later. By doing that, you get less sleep in by the time you need to wake up.
As for your homework issue, I suggest doing what I did and taking up any free time you have to do it. Whether it's in class or at lunch, use any idle time you have to do homework. I had a mindset of work at school, relax at home. So unless the homework was dire, I usually had no motivation to do it at home. To counter this, I used my free time in school to work. I had a decent amount of it, especially when I got an empty class period. By doing my homework at school, I reduced the amount I had to do at home to almost nothing every day, even before I had the free period.

That's something else I forgot. Thanks Miera for reminding me.
When I was in freshmen year I had a huge paper and project due for two separate classes. Unfortunately, during that time my parents were off at Grandma's again, checking up on her and doing a bunch of chores with her. My brother lived with us at the time and he was kind of a jackass to me. I did everything without him, which made me tired and stressed, and then he'd proceed to yell at me for doing things without him which made me more stressed. But the thing is, it took him forever to do things and they needed to be done ASAP, which just wasn't his style. This, of course, brought on stress. So I was triple stressed out, just from home. Add on my two huge assignments and I'm 5x stress.
Finally, I just broke down and cried to my English teacher. This guy was really cool too, and I'll always be thankful I had him instead of the other English teacher. I pretty much poured out everything I had (and I probably made him slightly uncomfortable because I was BAWLING), bu he assured me on some things about my brother and told me to take my time on my paper since I had such a work load at home, let alone his assignment and my project. With his paper out of the way, I managed to focus on the other project done, and after that, I started to work on his paper immediately and managed to finish it by his deadline anyway. But because I got to let all that frustration out (I had almost no friends at this point whom I felt close enough to talk with, hence why I just unloaded on my teacher), I finally calmed down enough to do things.