That's a big problem buddy, most likely the root cause. You need to start exercising. Lifting weights will improve your strength and endurance. And I say that as someone who doesn't like exercise or gyms but forces himself to go everyday.
Also make sure you're having enough protein acc to your body weight (if weight is 60kg then 60g protein everyday, ideally 90g). Cut out sugar and coffee, they are only short unhealthy bursts of energy but cause problems when you crash.
What's necessary is necessary. Doesn't matter what your weight is, your body still needs exercise. Period.