dilantin toxicity

A year ago I suffered a TBI in an auto mobile accident and have had grand-mal seizures from it. Recently my doctor upped my dilantin to 900mg a day and even though it didn't seem right i took it the way he told me to. That night my family called an ambulance for me because I was having trouble breathing, I felt really drunk and I couldn't stay conscious. My dilantin level was at 26 that night and it was at 56 the next day. Its been over two weeks since then and I haven't taken any more dilantin but I've still been having issues with spasms of my arms and it feels like my brain keeps "falling asleep" where I have trouble talking, I stutter, and I get really sleepy. The ER doctor said the symptoms would stop within 5 days so I was wondering why I still feel sick and if these symptoms will go away.