My dad keeps borrowing money from me

My dad is not able to work right now and is not able to make money. He keeps asking me if he could borrow money and now he owes me almost $200 and I’m getting sick of it. But I don’t know how to say no to him, I don’t want to see him struggle but I’m not gonna get that money back even when he says he’ll pay me back and I could’ve used it to help with my school stuff or just get things that I need or wanted. And I don’t know how to tell him that I don’t want to loan him anymore money because soon I’m not gonna have any and I’m still too young to get a job.