Mononucleosis and liver damage

Hello!  My seventeen year old son was diagnosed with Mono (thru Mono-spot test and blood work) last week and it's been a very rocky downhill road since then.  He started vomiting last Wednesday on top of the persistent cough and sore throat he was already experiencing.  And by Friday night he was becoming frighteningly jaundiced.  At the hospital late Friday night, they gave him supportive therapy including 1000ml of fluids, IV antibiotics, and IV ondansetron to control the nausea and vomiting.  His liver function tests were in the hundreds, his platelet count was low and his bilirubin count was also high.  They told me this was mono-induced hepatitis.  Today (Monday) he's still vomiting though not not as severely and his temp is finally normal without the help of ibuprofen.  He still has a persistent non-produictive cough and his color is not much better.  Our family doctor repeated the blood work this morning but the liver fuinction tests won't be available until later in the week.  

My question is what can I do to promote liver healing?  Will there be any long-term liver damage from this?  I have never seen this child so sick!

Sign me a worried mom