First day

Today was the first day in school and I haven't sleep for three days straight. It was a hard day to me since I don't know what to do about my sleeping problems nor why I'm losing sleep. This habit could ruin my future and I feel confused.

A sentence must always start with a capital letter. The personal pronoun "I" must always be capitalized too. For formal writing it is very important to know that the numbers are almost always written in their written form. A period is very important and is used to make new sentences, if there are no periods in your sentence it's called a "run-on" sentence (and most people will get confused reading with run-on sentences).

For this sentence it would be better for the preposition "of" to be used instead of the preposition "in".  The past tense verb "went" is more appropriate then the word "going", as it makes sense in the context of this sentence.The preposition “for” would be used here instead of the word “to”. For informal writing it is okay to place a “sad-face”, but for formal writing it should never be used (giving you this as a tip for both the informal and formal writing).

Below I will rewrite what your wrote with the corrections I gave you above. The corrections will be red and bold:

Today was the first day of school and I didn't sleep before I went to school. For three days it was so hard for me. But I can't sleep at night,so I don't know what to do. :(This tradition could make me lose my future, and I am confused.

*BONUS TIP*:

For sentences that are different from this one (for example talking about something positive and then talking about the negative) remember to place the “sad-face” after you addressed the negative, otherwise (talking about the positive or nothing in the negative zone and there is a sad-face) might be really confusing. Usually the “sad-face” would be placed after the sentence and not before it.

It makes sense for the “sad- face” to be placed after the sentence that you feel is sad, but placing it before the negative (in which is the reason for the sad face) might confuse it's (the article, etc.) readers. This extra tip is for anytime you want to put a “sad-face” and not sure when or where to place it (when the subject has both positive and negative things in it.)

The same thing goes for the positive. If you are talking about something bad, and then you place the smiley face before the you talk about the positive—the reason for the smiley to be there—then it would be really confusing as some may link the smiley to the negative talked about previously. But it is always good to make a distinction of where and why you are placing.

Smiley to be linked automatically to the positive and sad-face to automatically to the bad (and to be grammatically correct before placing them...but since they are used mostly only for informal conversation I don't think it would be such a big deal grammatically for the fact almost all informal conversation is already grammatically incorrect. Like, “i” instead of “I” or “u r” or “ur” instead of “you are..” and “your..”).

I hope that was helpful!! Keep studying hard in the English language and you will be great! You just need some more practice and you'll be great at it! Keep up the good hard work! I really hope I have helped you, and I hope the bonus tip has been helpful for you as well!

If you have any questions or problems in the English language let me know and I will help you in every area that I can. I hope you keep improving more and more in your studies of the English language!

Sincerely,

EffortofDevotion.