Do I owe expiation after I swore in a moment of anger that I would not eat from restaurants, and then I ate from them?

You are required to offer expiation for breaking your oath, as Allah Almighty says: "Its expiation is the feeding of ten poor people from the average of that which you feed your [own] families or clothing them or freeing a slave. But whoever finds not [the means to do so] - then a fast of three days." Anger does not prevent the oath from taking effect as long as you are conscious and aware of what you are saying.