boyfriend told me not to talk to him rest of morning

My boyfriend’s (33) son hasn’t been eating his breakfast lately because he’s been pretty sick. He’s expressed his frustration about it and i’ve (20) just been telling him if he doesn’t want to eat, he’ll just be hungry and he can eat at school. The poor boy hasn’t had much of an appetite due to excessive coughing and a sore throat. I don’t know what snapped in him but he got mad at me and told me not to talk to him in that way. I was super confused because… sure you can encourage a child to eat, but you can’t force them. Then I told him I’m just gonna leave the kitchen and go to the room because I’m not going to argue with him about this. I came back a few minutes later and said I don’t understand why he’s taking it out on me. He started giving me a bunch of attitude and I was like “don’t take this out on me, i eat my breakfast and drink my tea.” Then he was like, “don’t talk to me for the rest of the morning.” So I told him he can have McDonald’s for lunch. (i make him his breakfast lunch and dinner pretty much everyday btw🙃🙃)