My 2 years old son

Last June, my son have his first seizure, and getting more frequent from monthly, weekly to daily. The worst scenerio is having 5 seizures a day and vomitting alot afterward. Doctor has diagnose he has epilepsy, and starting with taking Tegretol. Having Tegretol made his seizure pattern from 2 min to 10 min, but not as intense. Increasing the dose seem to hold off his seizure to a weekly habit but he been jerking quite often. Doctor then decided ease off Tegretol and add Topiramate. His seizure stopped for 8 weeks, although jerking still existed but it only happened before sleep, so to us is easier to manage, but he was also very aggressive and no sweating somehow even in hot day. After full transition to Topiramate, my son have another week of seizure and jerk free. We thought it finally over, however, seizure back again and getting more frequent again. Thus, doctor said to ease off Topiramate and added clobazam. However, somehow his seizure duration has increase to more than 10 min, worst scenerio was 25 mins and jerk reappeared. Doctor seem very confidence with clobazam and increasing the dose and said clobazam is suppose help his jerking (i was thinking, the jerking appeared right after we added clobazam), but in some way it did show that clobazam can stop his jerking for few hours. I wonder is my son rejecting clobazam somehow so jerking reappear and increase dose make my son harder to reject therefore jerking reduce for few hours only. Anyway, doctor then added keppra, but also no improvement. I started thinking, why the medicine we used before can hold his seizure for 8 weeks but not the latter one which doctor think will work? Is my son getting worse or because some kind of medicine make him worse. Do you guys have similar circumstances? What will you do about that?