"Saturday morning."

I see this mistake a lot in Russian notebook entries - the titles are incorrectly capitalized. In English writing, all important words in a title must be capitalized. Only unimportant words inthe middle of the title (articles, conjunctions, some prepositions, etc.) can be left uncapitalized. For example: "Saturday Morning", "Saturday Morning in the Fall", "A Fall Saturday Morning", etc. Finally, there should be no period after a title. Correct is simply "Saturday Morning"

"It's been getting very cold out here recently. So it was hard to wake up today. My gf got sick because of mad cold."

To be grammatically correct, you need an article before 'cold'. "My gf got sick because of a mad cold." But there are better ways to construct the sentence. Here are two possibilities: "My gf came down with a mad cold.", "My gf got sick with a mad cold." Finally, here the adjective "mad" is slang that sounds funny in my part of the USA. I would use the word "brutal" to mean the same thing.

Saturday Morning.

It's been getting very cold out here recently. So it was hard to wake up today. My gf got sick because of a mad cold.