Not going to pretend like I’m an expert on cars, but, a grinding noise when you are in park and the car shuts off when put in gear sounds like a transmission problem. Also, check if the steering wheel is hard to turn. If it is, then the hydraulics have something wrong too.
Pretty sure it’s not solely an ignition problem, since you had that grinding issue however there probably is something wrong with it if your key won’t turn easily.
Find yourself a pro my friend