A rRecommendation

We capitalize the first letter of important words in titles,

Guys i, I really recommend that you to send at least one audio of yourself pronouncing a word each day andto get corrected by native speakers.

"I" is always capitalized.

I didn't realize that the whole time iI was pronouncing the (j/q/x) and (zh/ch/sh) improperly.

Now it feels like ias if I have a headache in my tongue.

Guys iEveryone, I really recommend that you to send at least one audio clip of yourself pronouncing a word each day and get corrected by native speakersto native speakers, to get corrections from those who speak your target language(s).

'Guys' is ok but does sound informal! Always use a capital 'I' for the pronoun. :)

All this time, I didn't realize that the whole time iI was pronouncing the (j/q/x) and (zh/ch/sh) improper sounds incorrectly.

Now, I feels like iI have a 'headache' in my tongue!

This is a jokey/impossible sentence, so I think it makes sense to use single quotation marks and an exclamation mark at the end!