I have two invisible physical illnesses, and suffer from depression (so a third one), and I have Sensory Processing Disorder (which is quite rare in a non-ASD adult), and people just don't 'get' this, or believe me because I look fine, and I have a toddler - because obviously, ill or disabled people can't or don't have children
I also like to dress as stylishly as possible and wear a bit of make-up because it cheers me up, ie if my body won't work properly, at least I can make it look nice, but this just compounds the problem. Because, again, disabled or ill people are never fashionable or well-turned out 
Another problem is that when people find out about my conditions, they start to talk to me in that horribly patronising way too many people talk to others with SN (newsflash - talk to people with SN like you would anyone else, ffs).
It's also meant that despite having a PhD, I have a crappy work history, one that in no way even starts to reflect my levels of intelligence, skills and qualifications. Bosses think you're a time-waster, or are swinging the lead, colleagues get fed up and intolerant, and those doing the employing would prefer a safer bet, health-wise, every time.