When it comes to study schedules, I think there's always that misconception that 'more hours = more information retained and better performance'. However, that is not always the case. If you're studying six hours STRAIGHT after school, you're overwhelming yourself and not giving yourself a proper break. It's great that you go on runs after school (physical exercise is very crucial to keeping a balanced mind) but studying for six hours straight afterwards is not ideal. Especially if you go up until 11:30pm every night. You need to eat dinner and get a good night's sleep.
When I studied for my HSC, I would usually study for three subjects max after school and same on the weekends. Sometimes I would reduce it down to two subjects if I felt that I was done for the day. I knew if I studied for all five subjects in one day, I would lose it and lose interest immediately. Plus, let's say, you already had two hours of Maths during school time and had a one hour class for SDD, there really isn't any point in adding so much effort into them after school hours if you already had done them during the day (if you get what I mean)? For each day of the week, nominate subjects you want to study per day depending on your timetable, if you have any extra curricular activities and if you have any tutoring. I usually had two hours of Maths tutoring after school every Tuesday. When I got home, I would not work any more further on Maths because I had already met my quota for the day. Another example is that I didn't have Ancient History on Mondays therefore I would study for Ancient after school to make up for it. It's all about creating balance between your school timetable and your after school activities. During the weekend, I would recommend taking either Saturday or Sunday off because it really does make a HUGE difference. Don't overwhelm yourself by studying all your subjects everyday.
Doing small chunks of study rather than big chunks makes it easier for you to concentrate. Try to study for one subject for 25 minutes then take a five minute break (actually get up from your desk, grab a glass of water, stretch, get something to eat, even go outside if you have time). Then repeat again for 1-2 more subjects. Once you're done with your 2-3 subjects, that's it. Give yourself a break. Take the night off. You should be in bed around 10pm so that you have enough energy for the next day.
Like PF mentioned above, try studying in a different environment. Though studying at your local library doesn't necessarily mean you will get work done. People prefer the white noise at libraries to concentrate. While people prefer to study at home. But when you study, you need to be at an environment that is similar to an exam hall. Avoid listening to music- you will end up distracting yourself. Avoid studying with your friends because at some point you will go off track (unless you're doing group work!). Timing yourself helps as well to get practice for your future exams
It's all about studying smart, not studying hard
Good luck!