Get a manscaper electric shaver/trimmer for the body hair. They have different settings so that you can take it down shorter and thinner instead of taking it all the way off if you are worried about keeping up appearances. If you decide to go further, then you can get women's disposable razors and shaving gel to go totally smooth.
As far as clothing, put together a "drag bag." That's a duffel bag to hold one or two complete outfits, wig, makeup, etc. That way you can pull it out when the parents are not around, get in a quick dressing session, clean up before they return, and then hide the bag when they return. But really, unless you are in danger of being thrown out on the street, coming out to your parents is a far better deal than sneaking around behind their backs.
Regarding your girlfriend, whatever you do, do not marry her or have a kid with her until and unless you resolve your gender situation first. Too many of us older girls who grew up in a society far more hostile and primitive than this one have convinced ourselves in our twenties that we were male, married a girl and had kids with her.
Then in our thirties and forties we started suffering really nasty physical health problems as the dysphoria we denied in our twenties came home to roost. The result is having to deal with a divorce and child support as well as transitioning, or having to drag our wives and children through a transition with us.
Neither situation is fair to your significant other. So in the name of fairness, address the gender situation before the relationship gets too serious.
