LOL - you don't have to go to medical school to be a "physical therapist"! Perhaps what your GF wants to be is a Physiatrist, aka rehabilitation physician, a doctor who specializes in physical (sports) medicine and rehabilitation?
Perhaps when she tells you to "do what you want" - maybe she actually means it with no hidden agenda or playing any games? She is obviously doing what she wants - why shouldn't you? If she is going to medical school ... you're not going to have a lot of lovey times together for 5 years (the 4 med school years will be slim - forget any prolonged quality time during her 1-year Internship) - although during her (1-3 year) Residency she will have a little more time to acknowledge the fact that you even exist.
IMHO - if you can't think of anything that you would rather do than cook - take the culinary courses ... and give it a year. If not - get your undergraduate degree, go on for you Masters and Doctorate - and work for a position where you can get tenure. Of course, I can think of nothing more detrimental to the educational system than an English teacher who is not dedicated and inspiring.
FWIW - my cousins used to run a lodge in Colorado - Tabby and her husband were my Dad's age - they ran the lodge, their daughter Claudia (my age) and her husband (she ran the front of the restaurant - he was an Austrian Chef and ran the kitchen) ... the hours were "from can till can't + plus whatever else was needed".
"It ain't what you don't know that gets you in trouble. It's what you know for sure that just ain't so." - Mark Twain