Hi guys, I used to study eEnglish in an academy in the past, however since I started the university, I stop doing this.

I wasn´’t really good speaking in eEnglish, but I could defend my self wellbe understood, so it´’s really sad seeing how I´’ve worsened these years.

English is always capitalized.

I hope this app help tos me to improve a lot.

Great job, keep it up!

FIRST TEXT I DO IN THIS APPirst Text I Write in this App

changed to title case and "texts" are usually "written" or "created" instead of "done"

Hi guys, I used to study eEnglish in an academy in the past, howeverbut since I started the university, I stopped doing this.

If you wanted to use "however," it could look like this:

Hi guys, I used to study English in an academy in the past; however, since I started university, I stopped doing this.

I wasn´'t really good at speaking in eEnglish, but I could defend my selfget by well, so it´'s really sad seeing how I´'ve worsened these years.

"defend myself" sounds like there is physical violence or insulting language

"get by well" or "manage well" sound like you are saying you could use the language OK

I hope this app help tos me to improve a lot.

or "helps me improve a lot"

Hi guys,. I used to study eEnglish in an academy in the past, hat school. However, since I started the university, I stop ped (doing this).

"I used to" already means you did it in the past, so no need to repeat that. The end in parentheses is optional here.

I wasn´'t really good at speaking in eEnglish, but I could [defend my self well ?], so it´'s really sad seeing how I´'ve gotten worsened over these years.

English is always capitalized.
The part in brackets does not make sense here. Do you mean you did well at school? If so, you might say, "but I did well in class."

I hope this appwebsite help tos me to improve a lot.

This is a website, not an application that can be downloaded onto a phone.