First of all, thank you brother.
Secondly, not the most fun situation, but you'll grow a hell of a lot from it I'm sure. I don't know hen your examinations are due but Steemit is no platform to earn money quick (maybe it was but nowawadays I would say it is a slow process). If Steemit is your only option I would do high-quality and well-produced d.tube and d.live videos and hope for upvotes from those accounts. Myself and many others have made profits doing that (although it's more of a biproduct of good content than anything else). Also once you get the flow up, filming and editing a d.tube video can be done within an hour if your efficient. But remember again, your content must be good, sexy thumbnail etc. Otherwise your just wasting time.
Regardless I wouldn't spend more than 2-3 hours a day on Steemit, that leaves 12-13 hours of time where you have the possibility to study, which should be more than enough. Sending you energy brother 👊🏼