It's tough to find the best way to deflect that question, "what do you do?". Our self esteem and identity are tied to that very big question. Until I hit 50, and CF's wrath stopped any hope for working again, I didn't really have this problem. If anything I felt guilty because I did what most people, myself included, dream of doing.
I'm a genuinely happy person. I'm happy when things are good and happy when it sucks. Mostly. I've been very lucky, to the point where my riches are embarrassing. If you want a conversation stopper, tell someone that you are a Senior Scientist, or CEO of a well known company. I remember seeing a good friend at a 20th class reunion (high school) and she summed up the twenty years absence noting a marriage, kids and divorce from a man who was president of an oil company. A few years earlier I was working in the oil industry and I was married to a geophysicist. Denver had 1,100 oil companies, so I asked, "what oil company?". It was a big one like Exxon, England. I was speechless, a rare thing for me. My old dear friend had been very lucky as well. She had listed her goals when we were in highschool and achieved everything she set out to do and be.
An old rule is you never ask a farmer or rancher how much land they have or something like that. It's taken as nosey at best and rude at worst because you're asking in essence how rich or poor a person is. Being asked what you do rarely has to do with the facts of your employment any more than a tin horn asking how many cattle a rancher is raising has to do with agriculture. It's an ice breaker.
I was awarded a doctorate when I was 19. I'm so sensitive about the whole thing that I rarely tell anyone. Like you and many others, just explaining that you have been trying to stay alive and have something resembling a life is not what we would like to say. We don't necessarily look sick, in fact we look younger and healthier than most people. My best friend was just wondering about CF and she asked me how CF could be so painful. Of course CF doesn't hurt, it is simply thicker fluids than normal. This imbalance makes the mucus in my pancreas so thick that enzymes don't make it to the duodenum. The enzymes ultimately break through the mucus and then digest the pancreas and so on and on. Nope that's not it either.
My pet answer, assuming a friendly atmosphere is to say "I'm a drug dealer". I figure, with all the drugs out there, somebody has to be a dealer. It's playful but not sure everyone has a great sense of humor. In any case, I suggest you lie. Pick one you can get a reaction and you can take it from there. Choose one or two things that you have had fun doing. In the last oil bust, Denver went from 1,100 oil companies to 115 or so, a good friend with a degree in nuclear engineering, using his extensive experience in math and science to work in geophysics and now among the thousands of highly qualified people, unemployed, came up with being a botique kennel, professional dog walker and a thawer. Yeah a person who will pick up your house keys and go to your house and take some food out of the freezer for dinner.
You have touched my heart with a dilemma that probably chokes most of us. Just a matter of time. You do all that you can.
LL