Do not let him isolate you from your friends or parents.
You ask "Do you think he is suffering from a mental disorder or is it just a character problem"? By this you seem to indicate that character problems are less worse than mental disorders. This need not be so. Character problems are by psychologist called "personality disorders" and they are, unfortunately, difficult to cure.
SSRI medicines might be able to cure the obessive elements of your husband's behaviour, but they may have side effects which he finds unaccepable. Psychotherapy might also help, and does not have problematic side effects.