I believe that a picture is worth a thousand words, so here we go:
https://imgur.com/a/B053irSBasically, all you need to do is:
1 - Build up your GP offices little by little, starting at around 3 up to 6-7 by wave 15 and 10+ by wave 30.
2 - Train your staff continuously, get a few specialists (surgery/psych/etc.) and put all the others as treatment/diagnostic only
3 - Once your reputation maxes out, jack up all the prices by 100% (you'll see lots of complaints but that's how you'll stay afloat)
4 - After each wave is past the assistants, close the reception to let them rest until the beginning of the next wave
The rest is just a bit of micromanagement, I bought 1 of each robo-janitor to ease off on the whole hiring janitors process at first but you don't really need to.