I don’t want more stress

Do they need the help financially, or do they just want you to get job experience? It makes a difference. Talk to them about why. Tell them how you feel. Work it out together. If they don't want to talk, I would say something like, "I know that I am your kid, but I am going to be an adult very soon, and adults talk about disagreements and work things out together." Your feelings are valid, but they ARE feeding and housing you, and that's not always easy. If they asked due to familial financial hardship: Sometimes your responsibility to your family has to trump your extracurricular activities. That is a matter of priorities.