For direct relief, doing some bodily actions, outdoor game, singing, chanting of Mantra etc. is helpful.
Causes for stress are unlike for special persons. I request you to look at and find out those issues causing stress in you. You are aware that stress causes a great escape in the level of our force and notice.
A. Say, in lessons some subjects because you more stress that means you are not able to cope up that picky theme or topic. The right remedy is learning the theme from books, teachers or friends who are apt to it.
B. One factor for stress is low corporal energy. Famous person said that a strong mind needs strong body. Here you have to make in order efforts for work out, outdoor sports, well habits, healthy food, rising before sun rise, eating before sunset / keep away from late evening eating / pass up junk foods etc.
C. Second issue is your mental energy that also needs to be build up with watchful and guided efforts like Yoga, Pranayama, Surya Namaskar, prayer to rising sun chanting Gayatri Mantra, thought ( maybe following your relations usual prayers or rites) etc.
D. Third Factor is power of Chitta (deep consciousness) which is likely for your learn by rote and put in order of knowledge. This power can also be build up with aware effort like get rid of wasters of your think about power (the power which shows you unlike pictures while you are learning) in concert tape games, needless chats, watching cricket on TV, too much of social media etc. and to replace those with real action like outdoor sports, walking, running, singing, drama, live music show etc. Also at this stage better to restrain ourselves from pointless links with reverse sex as it sources chains of add-ons and use up lot of mental powers.