Feeling Sleepy

NOTE: The original is possible, but the correction above is clearer.

OPTION A: Maybe it's because of the weather,; it's getting hot and humid recently.¶
OPTION B: Maybe it's because of the weather; Shanghai has been hot and humid recently.

Some readers might not know you are in the Shanghai metro area; I included that information.

MOPTION A: Or maybe it's because I didn't have a good sleep last night.¶
OPTION B: Or perhaps I didn't sleep well last night.

OPTION B is more succinct.

Maybe bothOPTION A: Maybe both factors were involved.¶
OPTION B: Or perhaps both of these facts were at play.

OPTION A: I tried to letovercome the sleepy feeling go away by drinkinginess by drinking a big cup of coffee.¶
OPTION B: I tried to shake out the drowsiness with a big cup of coffee.

Maybe it's because of the weather,; it's getting hot and humid recently.

these are two independent clauses so you can't connect them with a comma. It's a grammatical error called "comma splice" which is a run-on sentence

Maybe it's both.

I tried to lget rid of the sleepy feeling go away by drinking a big cup of coffee.

There's noIt didn't help.

Maybe it's because of the weather, it's gettingbeen hot and humid recently.

Maybe it's because I didn't have a good sleep well last night.

Sleep is more commonly used as a verb rather than a noun.
'didn't get a good night's sleep would' also work well here.

My apartment is near a small road, and someone along the road had a loud phone call along the road last night and woke me up.

I would include the 'along the road' prepositional phrase first since the concept of a road was just introduced.

I tried to lget rid of the sleepy feeling go away by drinking a big cup of coffee.

There's noIt wasn't helpful.

I decided to have a walk in the building and wsplash my face with some cold water.

'Splash' is a bit more idiomatic here.

Maybe it's because of the weather,; it's gettingbeen hot and humid recently.

1) Because both clauses are independent, using a comma would be considered a comma splice. Instead, one of the clauses may contain a conjunction such as and, but or, yet, etc. You may also separate the clauses with a period or semicolon
2) Since you're speaking about an event that has and is currently occurring, been is used instead of getting, because getting implies a future action.

Maybe it's because I didn't have a good sleep well last night.

"Didn't have a good sleep" is good and can work. "didn't sleep well" is a little more natural.