hi dad, welcome. meds for bipolar take about 21-30 days to become theraputic. so give it time to see results. on the other hand it takes time to see what works. sometimes multiple meds are tried for the best result. it's very wise of you to have gotten him help so soon.
as for how to deal with his mood. it's difficult to give you an answer since he seems to be rapid cycling at this time. this site may help:
http://www.webmd.com/bipolar-disorde...polar-disorder
this does not mean that his doc can't get it under control. it just takes time. i've been dx'ed bipolar for 21 yrs. now. virtually no episodes or mild since i was on the best meds for me. i stayed in the psych ward for about 40 days so we could be assured my meds worked. for me that was the key for improvement. everyone benefits from different cocktail mixes of meds. i returned to my corporate career. once this is sorted out he'll probably do well and can resume his studies and have a quite normal life. i hope this reassures you somewhat. keep us posted on how you both are doing. we're here for you.
you may want to post in the "bipolar forum" too. lots of us there.