OPTION A: My Dear Friends: ¶
¶
I am anxious, I am looking forward to hearing from you all.all of you. ¶
OPTION B: Dear Friends: I am looking forward to exchanging ideas with all of you. ¶
¶

In some parts of the USA, the phrase "you all" is used. In standard English, the phrase "all of you" is more common.

LALSO POSSIBLE: My life here isn't as fun bed of roses, as it may seem to youon the surface.

IDIOM: a bed of roses → https://dictionary.cambridge.org/dictionary/english-chinese-simplified/bed-of-roses

PThere are piles of homework, the pressure of examinations, and loads of delicate things thatcomplex affair distract me all make itfeel life a burden for me.

COMMENT: I often feel this way. Once or twice I meditate for 20-30 minutes. (这感觉就像一个"精神浴"，然后我感觉更清晰。)

I amfeel like like a drop in thea vast sea.

Do answer my letter ASAP.(If you are writing a *letter* to someone, this is possible.)

My Ddear Ffriends: ¶
,¶
¶
I am anxious to hear from you all.

For the punctuation of English-language letters, you can look this this webpage from the University of Sussex: https://www.sussex.ac.uk/informatics/punctuation/essaysandletters/letters.

DoPlease answer my letter ASAP.

If you want to be extremely forceful, then "Do" is completely correct. But I personally would never write in that tone.

I am like a dropbut a mere drop of water in the deep sea.