How difficult is it for him to change Doctors?   If he's dropping the
levels of his AED without the Dr. supervising it, he might get side effects
that should be watched for.   That's not his job (or your's), it's the
Prescribing Doctor's.   I expect that's why Malpractice Insurance is so
costly.
 Have you ever talked to the Doctor, and would he (your fiance) want you
to? Perhaps the Doctor is not aware of the way he's reacting to the
Medication, and often an outside witness is a more reliable source of how
we're behaving than we might be ourselves.
   Alternatively, if he's got an appointment with his Doctor soon, you
could compose a description (like you did above and earlier), of the
behaviours you're concerned about, and how the Med. has changed his
personality.   Make sure you include the part above and on earlier posts
about him not caring and giving up on everything -- that should be something
the Dr. should be made aware of, as some of those things, including
depression, can be a negative warning with some of the Anti-Ep. Drugs, and
might signal a need to change (again! :-<  ).
    I think it was 'Howdy Dave' when he was posting more, who said he had
to try something like 6? or 7 Meds. over the course of many years before he
found the ones that worked for him.

  Another thing -- are you near a large city that has an Epilepsy
Association, and would he be willing to go to 2 or 3 'group' sessions that
some of them have either afternoons or evenings to discuss (among people in
like condition)  what it's like and how they're feeling about having to live
like this?   The one near me has consultants who meet one-on-one with either
newly diagnosed people or people and their family members.   If he's been
coping in various forms with this for a number of years, he may not be
interested in that, and thus might not get anything out of it.  /G.