Help needed epilepsy type for my son

Hi, All, I'm new to this forum. Hope I can get myself understood with my poor English.

My son was just diagnosed with Epilepsy two weeks ago, the the type is still in observation. My son is 4 years old. Everything has been normal untill he was 1 yr+, we found he always easily fell down even when he is running or walking. We did not place much attention thought it is normal as the yourng boy is leaning to walk. from 2~3 he seems to be quite ok although occassionally falls down then as usual, he immediately resume what he was doing within 2 seconds.

Things became worse after he turns 3, after one normal fever cause by flu, we found he easily falls down and with / without shaking, again, this happens very occassionally and he resumes what he was doing in 3 seconds or less. We could not observe absence seizure. We sent him to hospital, doctor did EEG but found nothing. Blood test and cardiological tests also indicated normal. He was discharged thereafter.

He has been okay though occassionall it still happen and we observed the happening is always when he is sleepy or tiring. Early of the month he experienced frequent falling down again, within 2 days. Sometime he walks then stops, eyes tend to look up (not always), then fall down (sometimes hits the head then cry) within 1 second, he could resume what he was doing, and he knows he had a fall. sometimes, while siting or playing his body just seem to have loss of balance and he could adjust back immediately.  Most of the time, his eye ball stopped movement and his head just turns down or aside. 

Again we sent him to the hospital, and this time, during EEG, he had once happening and the doctor immediately concluded as Epilepsy. While staying in hospital, doctor gave him Phenobarbitone, first with injection, then turns to tablets (4.5 tablets). There was no seizure happening, but we observed he was extremely active and poor muscle coordination. The doctor suggests to change the drug to Carbamazepine (liquid). After oservation for 1 week, my son was discharged. He did second EEG, MRI, DNA test, everything showed normal.

The first a few days at home was plesent, he is more active than before (he used to be very quiet and lonely in school), no seizure happening in 4 days, during these days he consumes 6ml Carbamazeping (Tegretol) + 3 tablets of Phenobarbitone. On the 5th day, as appointed, we visited the doctor and doctor asked us to change to 7.5ml Phenobarbitone (without Carbamazeping) in the morning and 7.5ml Phenobarbitone (+ 3 tablets of Carbamazeping) in the afternoon, from the next day. 

The 6th day after discharging, my son consumes 7.5ml Phenobarbitone and became very sleepy, has has the above descriped seizure one in a while (can be a few times until he could not stand a lone). This has lasted for 6 days and we really worried becuase every day he has seizure happeing more than 20 times! We found this could be triggered by Carbamazeping because after the medicine he is very sleepy (but refused to sleep).

We plan to visit the doctor again tomorrow (today is Sunday). But in the meantime, can anyone here help to advise what kind of Epilepsy my son is having? As mentioned, almost all seizures he has happen when he is sleepy (after medicine) or very tired (after playing in the playground, when playing with others he is okay). Some times we could not differentiate it was a seizure or he was just too sleepy (with only head movement), once he is eleeping or awake from sleep, everything seems okay agian. Another question, is Carbamazeping really effective for his type of Epilepsy? Because I feel my son is getting worse with is as it casues drowsiness which making my son's seizure happen more frquently.

We have spent sleepless nights for 3 weeks and as father I realy worry about my son. I love him.

Thank you all for your advice!