Going to hit on a few points that seem to be missed by the majority. Your 15, I assume you live at home with your parents who do most of the cooking and all of the buying of groceries. As for you getting 5 hours of sleep a night, you need to prioritize what you are doing. Get a piece of paper and write out what you do in a day and what times, I guarantee your time efficiency is lacking greatly. I grew up on a dairy farm and had to be up at 0400 to milk cows and do chores, I went to sleep at 9PM every night, that's 7hours. I Cannot imagine your schedule being so busy that it leads to 5hours of sleep unless you have a job or a video game/tv habit that needs quenched. Second I would recommend getting a part time gig at the local all you can eat buffet. Even if you work two days a week that's two days of massive amounts of calories you can consume, and also will put a little more money in your pocket to help out on the non working days if you so chose to spend your money on foods.
Not sure how your school is set up but I had lifting as a class all through HS. 5/3/1 should work great done in class, your lower body lifts are good so however your programming them I would stay with it, need to bump the upper body lifts a bit, try adding in a first set last ie 65x5 75x5 85x5+ 65x3x5-8 mix a pull between your press sets to save time.
Basically.
You need to get more sleep each night.... do whatever you need to do to make this happen, at least have one day a week where you sleep as long as you want
Get a part time job at a food service place, preferably an all you can eat since that's your main point.
R
Stay on 5/3/1 since it is working for you. Maybe drop to a 2x a week template ie Deadlift/Press/ Pullups Squat/ Bench/ Row
Your 15, don't' put to much pressure on yourself to be a beast. One day you will be on your own and in control of your environment, till then endure. When you first start out on your own its going to get way worse. Stan Efferding has some great knowledge he gives out for free as someone already posted. Best of luck to you