Your parents may be between a rock and a hard place in the sense that it is clear they are not happy with something you are doing or with the situation but are bound by their initial promise that they would let you live there "forever" It may be nothing short of that you are all butting heads because truthfully it would be best for you to get out on your own and move out (which I realize you are working on) but having framed the situation as if being parents that are ok with you living there forever, they are hard pressed to say they may just want you to live on your own now. And this may be their dilemma causing a lot of stress and frustration in their minds. And it's coming out as rude, sometimes dismissive attitudes. I know, I may be way off, but I'm speaking as a parent myself of adult children.

As for the time being, if you opt out of having an honest conversation which is a completely acceptable choice, then find ways to limit the time you have that will risk uncomfortable situations. find way to stay out, or away, give both parties time to have some peaceful solitude. I don't know how hard that would be but it's worth looking into.

hope this helps.