bleepbloopbop
Anyway maybe I'm just pissy
nah you are 1000% correct, medical gatekeeping is fucking bullshit.
also my good friend with PCOS is also trans now that I think about it 
I was wondering why this post sounded so familiar
did they tell you what the code was exactly? I'm struggling to figure out what code would be thrown for a minor head gasket leak on a 2003 vehicle... Misfire code would have to be a pretty bad leak, and low coolant idk, seems like a 2003 wouldn't even have a sensor for that, I know cars I've owned didn't. It's possible they're bullshitting you, or that they're telling the truth but the code is unrelated.
Whatever it is, I would bet you could get the code to go away long enough to pass smog, though I'm not very familiar with CA rules. It would eventually get worse though. I would get them to give you the exact trouble codes it threw, or take it someplace else that will read them for free/cheap. Not knowing what those are really changes my answer
As far as doing it yourself: it's a big job but with enough time and tools and patience and shit you probably could. The thing that will drive up the cost/PITA factor even more though, is that if you're doing the head gasket you really should take the head to a machine shop to get milled perfectly flat again, to give it the best possible chance of lasting as long as possible. The last time I did this, I ended up having shot valves in the head that had to be replaced as well (also a suzuki coincidentally), but yours probably aren't that bad.
If you were in the rust belt I'd be telling you to consider throwing in the towel on the car, but in CA its more likely to be worth fixing, as it won't rust out from under you in the next 2-5 years lol.
But I would HEAVILY encourage you to check for yourself what the codes are, get some second opinions, and look for signs of head gasket leaks (coolant in the cylinder will cause it the exhaust to have white smoke, coolant in the oil will make it lighter and more opaque like a milkshake, and probably leave a residue on the oil cap).
Either way I don't think there's much sense in throwing it away until/unless you have to.
Oh, and in addition to the retirement program another commenter mentioned, there is also a program where the state will pay up to $1200 towards an emissions related repair. Its a bureaucratic process and unclear if your repair would qualify but it seems like it would if it caused you to fail smog. I think you'd have to take it for the smog test and have it fail before you could apply for that. link: https://www.bar.ca.gov/consumer/consumer-assistance-program/index#otheroptions
good catch, fixed
yeah this, feature phones often have google maps now.