Hmmm.. You know guys too need assuarance and love. So it would be nice of you to give more and expect a little at this time. You take the step forward and do things for him. Support him in academics, in other stuff. Make him tell you everythign so he gets lighter. "LISTEN" to him.. trust me that works wonders. Listen to everythign what he has to say. You text him, call him and ask him if he was ok... But i guess ur question is whether u dont want to sound clingy.. In this case.. u would be making him feel better not being clingy. He needs someone and guys I know.. being a guy.. I will never say clearly that i "need" u when im in trouble. Cook for him, give him a lovely time so he forgets his worries for sometime atleast. And im sure ur smart enough to deal with it. Remember ur not being sticky and clingyur jus beign supportive... But yes dont over do it !!
Good luck