I think it's really unfortunate that he clearly has no understanding (nor has made much of an attempt judging by your post) of what mental illness is really like. To me, it's not "illness" if it isn't impacting your daily life any more than the normal stress of the rat race.

Unfortunately, other than supplying him with information to help him understand, I can only suggest finding someone who will support you fully whether or not he really understands you situation. Life is hard enough already without being with someone who will make it worse by their very attitude. Sadly, some people are just convinced that people with mental illness are just making mountains out of molehills and will not open their minds to the idea it is as much an illness as any other incurable disease.

I'm sorry to be so negative. I wish there was something positive I could say but I see no redeeming qualities in the attitude of this individual.