Hey Carlin!
It's a shame you're not in Perth; there's a few of us here balancing health issues with mustachianism / life in general.
My story: sick in a very vague way, on and off, from about fifteen or sixteen. Saw many doctors over the years who diagnosed me with all kinds of things, mostly CFS or "a bad virus". None of them ever made the connection with my hand and wrist pain and thought heck, maybe all this is related. Eventually a good GP referred me to a rheumatologist who took all of five minutes to work out that I have inflammatory / autoimmune arthritis, probably systemic lupus (I'll never get a definitive diagnosis of which type of autoimmune arthritis for a range of reasons). Subsequent to that, a better rheumatologist diagnosed me with fibromyalgia and hypermobile joints in my thumbs and wrists additional to the arthritis.
I would recommend seeing different types of specialists if you can. My main symptom has always been fatigue; I had no idea that I was actually in all that much pain other than recurrent issues with hands and wrists, which sounds silly but whatever you experience is just normal to you, right? Apparently this is quite common with autoimmune arthritis and GPs are now being trained to question more closely when fatigue is the defining symptom. Some people with autoimmune arthritis produce blood markers that can be found via simple blood tests, and others do not, but it's worth a shot and, in my opinion, worth seeing a rheumatologist to rule it out.
I was diagnosed at the age of 24 or 25. I'd already established my career and I'm lucky enough to be a high earner. I was also already in a committed relationship with a very high earner (now my husband) and I am exceptionally lucky in that regard, as I do not have a family safety net to fall back on. If I did not have my husband, I would have no financial safety net at all aside from my own income and savings, and Australia's social safety net for which I am very grateful.
My health is managed via medication (anti-malarials, which thankfully do not have bad side effects at all), working fewer hours, taking on less stress in all areas of my life, having good boundaries (which for me has involved seeing a psychologist to learn how to 'do' boundaries), eating well and staying active in the ways that don't put pressure on my joints. The biggest difference for me has come from taking meds, lowering stress and working less. Those three things together make 95% of the difference.
I used to be an English Language teacher, but decided to leave this behind as the requirements of the work are full time hours.
I currently work in an office job with flexible working arrangements around my health, yet hope to pursue other work/employment/means of income in the future. However if this health condition continues, then I will be restricted in my employment options to jobs with flexible working arrangements, and a lower income due to working less hours.
I'm surprised you can't work as a teacher part time, but you'd know better than I would!
Yep, my career is restricted to employers who will basically not mind if I call in sick on a regular basis and only work three - four days a week. I've been working four days a week for almost two years now. About to start parental leave (woo!) but when I come back to work, I will try my damnedest to only ever work three days a week again until I FIRE.
Government tends to be good for this - at least in WA. Since dropping down to four days a week I've still been offered promotions, and people in my area who work three days a week have been offered promotions too. We have reasonably generous sick leave and flexible working arrangements.
The other thought that popped into my mind was, is there something you could retrain in that lends itself to only working part-time and still making good money? Book keeping, or something like that? Might be worth starting a separate thread on careers that earn well, can be done part-time and only require minimal training / qualifications so that you don't spend years and years getting a degree if that's not what you want to do.
As for how my health issues interact with FIRE: there are
direct costs associated with my disease - medication, medical appointments, all that kind of thing. My medical costs are our biggest category of spending after our mortgage. There are
indirect costs: we've recently hired a cleaner to do a 'deep clean' once a month because my hands and wrists can't handle the real scrubbing a bathroom occasionally needs (my husband works long hours, so I wasn't willing to put sole responsibility for deep cleaning on him), I use air con and heating more than someone who can regulate their own temperature better would, we sometimes end up getting convenience food or paying for other conveniences. Basically, lots of money saving 'tips' rely on time and energy. I usually have free time, but I don't often have energy - I suspect you'll be familiar with that quandary: free time is NOT the same thing as free energy to spend on something. There's the
opportunity cost: if I wasn't sick, I could work more and I would probably have taken a promotion or three by now that I've turned down due to needing to manage my stress. I would maybe even have a side hustle on top of a demanding full-time job, like many on this forum do.
On the other hand: there is no better motivation for becoming FI than
knowing that you may not always be able to earn an income. I don't assume I'll be physically capable of working past about 45: many people with systemic lupus end up on the disability support pension.