How do you say "I quickly forgot..." (As in an emotion you were feeling)
If you forgot your hunger because of work or study, you can say 废寝忘食, which means you work/study too hard to eat/sleep.
PS: You can not say 废寝忘食 for a girl.

for this sentence "At the beginning of the date I was really hungry, but after talking with her for a couple of minutes I quickly forgot my hunger", you can say:
我刚见到她的时候还饿得很，但和她聊了几分钟之后很快就被我抛到脑后了。