I'm upset that my boyfriend didn't get me anything while he was out
Did you ask him to get you something?
Yes, I hate him for that he's such a selfish bastard. He never listens to me
Did you ask him to pick something up for you? Maybe he just forgot. I would ask him to work on remembering what you ask him to do.
I want him to apologize and get me flowers.
I think that you should remind him more next time. I think that it would have be considerate for him to pick up your items since he was out, but maybe he had just forgotten.