The Difference between Big & Large

In genreal, both of the two words are used to describe something concrete.
However, they are slightly different.

BIG: It can describe concretely in size and abstractly in something important. For instance, "Tonight is going to be a big night for him." which implys that the night is important to him. Also, it sometimes makes readers
confused. " He is a big man." which not only means that he is physically big but also means he is important.

LARGE: It can also abstractly and concretely describe in size and volume. For instance, 1) a large house 2) a large geographical area 3) a large salary, they are touchable and conconcrete.

hello,this is Ruby who lacked of sleep

Good morning, everyone! Actually, I'm in duty now. My so-and-so boss hasn't come yet, so I am so eager
to finish the first post! Can you see how eager I am? No? Alright, it's ok if you don't see that. What else can I say...hmm... Oh,yes, I didn't get a good sleep last night and I ascribed that to the TV show called "Amazing World" and the nervousness of the coming work. What on the earth is "Amazing World" ? Haha! Is is不可思議的世界. I tossed and turned millions of times in the night and i was awaken by my roommates who got home late. I wanted to sleep but my body just wouldn't meet my need. There's one thing I can be so sure is that I fear the darkness and I worry so much about my work. In fact, work is not the only thing I feel uneasy.
Something makes me feel anxious for and it does form a turbulence in my mind.