Rant !sorry it's long !

I live with my in laws and for WAY longer than I've wanted to but times are tight and moving into a place will put us into an uncomfortable money situation . We don't pay rent here but we do have a bill that was assigned to us to pay and we buy EVERYTHING we need (food,gas,necessities etc) basically as if we our renting a room. There are times that we do run out of food and we use some of my in laws food or if we run out of toilet paper then we ask for some . Am I selfish that I get very annoyed when they do the same to us ? I buy everything name brand when it comes to necessities cause I hate having cheap quality product but they buy everything generic! (For example I buy Tide, or Gain detergent and they buy Sun or off brand detergent just because they want too) but where I get annoyed is that they use up OUR stuff when they see it but they don't use theirs!!! I'm sorry if I sound selfish but damn if you want to use the good stuff then BUY the good stuff instead of using mine and not even replacing what you use ! Smh am I overreacting or is it something to be mad at ?