tTo nNew bBeginnings

I've seen this application when I was scrolling on iInstagram.

I stuck a problem whichOne of my problems is that I couldn't speak English.

This problem ruined my life, every time, everywhere and now.

But INow, I am starting a new life but this situation will not be before decides, and I will try to improve my current situation.

I am really in delusional.

I modified your sentence to sound more natural. By the way, you're not delusional. You need to practice improving your English, and you can do that here.

tTo nNew bBeginnings

Titles have special capitalization rules.
"Begins" is a verb (he begins to...) and "beginnings" is a noun

I've seen this application saw this website when I was scrolling on iInstagram.

LangCorrect is a website, not an application.
Names (Instagram, LangCorrect) are capitalized

I've been stuck on a problem which I could, that I can't speak English.

This is a past and current problem, so you would use the "I have been..." structure.

This problem is ruineding my life, everytime everywhere and nowin all aspects.

This is an ongoing problem for you, and your life is not over yet => it is ruining your life.
The "every time, everywhere, and now" sentiment can better be expressed as "in all aspects"

But II am starting a new life, but this situation will not be before decidesit will take time for my situation to really improve.

Avoid repeating several "buts" in a row.
This sentence does not mean anything in English, but did you mean "decades" instead of "decides"? If so, my edit reflects this meaning.

I am really in delusional.

We would typically describe the person as being delusional, rather than say they are in a delusion.

tTo new beginsnings.

I've seen this application when I was scrolling on iInstagram.

I have been stuck with a problem whichere I couldn't speak English.

The correction is grammatically correct and close to your original sentence, but it doesn't sound very natural. I would probably say something like: It just so happens I have been struggling with a problem with speaking English.

This problem has ruined my life, everytime everywhere and now.

You don't need to say something like every time, everywhere and now. Instead, you could say: This has been a problem my whole life.

But I start a new life but this situation will not be before decidesfrom here on out, I will start a new life.

This sentence's meaning is a little tricky to figure out.

I am really in delusion

I am not sure what this is trying to say. I don't think you need it though to get the overall point through.