The funny thing is that when i read this post i was lying in bed feeling completely unmotivated and tired - though i had been lying in bed for the past 2 or 3 hours. Its only 8.30pm and i was ready to just go to bed, skip writing a post because i felt too tired to do it. But then suddenly after reading your comment i got a burst of energy!!
So what gives me my energy? Motivation, positivity and food. Because the truth is, if i didnt eat as much as i do i wouldnt be able to workout so often as i do... because yes, i do workout often and it does happen that i do both cardio and strength in one day. I also study and work hard the hours i am in school as well as several hours after school! However similar to the person who commented - i am an introvert and so spending too much time with people can drain my energy and i then recharge by being on my own. Which is pretty much what i have done today... i havent been very social and have turned off social media this evening as i just didnt have the energy for it. But with my boyfriend and my friends they give me energy, i enjoy spending time with them and they make me happy. Though i do of course need my breaks!! XD
I would suggest that you look over your daily life, what you are doing and what you need to do. Are you sleeping enough each day? Eating enough? Try adding in an extra snack or some green tea/caffeine or extra water as well as some extra carbs as that can give you energy. Take a powernap after school if that helps and then maybe go for a walk or do some meditation or yoga... becauase even if it sounds strange, exercise should give you energy!
When i was overexercising and on my way to a burn out, then i would feel completely drained after working out. I cancelled alot of plans and missed out on things because i felt so physically and mentally tired. Now when i exercise balanced and listen to my body... i can do a 6.30am morning workout, be in school from 8-4pm, come home and study and then do something in the evening and have energy for it all - feel happy the whole day! Though could i live on 5-6 hours sleep everyday? No i couldnt, but what i wanted to say was that exercise GIVES me energy even if i work hard while exercising - and thats the way it should be!!