Let's talk about a new life

“New life” without “a” is more of a generalisation about “new life in general” whereas it seems like you’re talking about a single new life for one person specifically in this context

Not when you said “Tomorrow I’m going to start a new life to become the best version of myself” and after somea few days or weeks, you stop because you a’re too lazy to gocarry on.

The contraction “I’m” instead of “I am” helps make it sound less formal

When I talk about a new life, I talk about every single day when you wake up and do these little things you plan to do, every day even if you a’re too busy, too tired and do non’t have any motivation.

Contractions make it sound less formal

Because to successed, you need to make more effort.

You do non’t really need motivation but discipline etand for that you musthave to do what you plan to without thinking about anything. else.

Maybe rephrase to: “what you need is discipline, not motivation” to make it sound more natural English

Let's tTalk aAbout nA New lLife

Let’s talk about a new life, ¶
¶
¶
I mean a new life for real.

Not when you saidy “Tomorrow, I'm going to start a new life to become the best version of myself” and after somea few days or weeks, you stop because you are too lazy to go onkeep it up.

When I talk about a new life, I'm talking about every single day when you wake up and do these little things you plan to do, e. Every day - even if you are too busy, too tired and do not have anyno motivation.

Because to successed, you need to make morea lot of effort.

You do non't really need motivation but discipline et f. For that, you must do what you plan to without thinking about anythinggetting distracted.

Let'’s tTalk aAbout na New lLife

Title capitalization rules

Let’s talk about a new life, ¶
¶
. I mean a new life, for real.

Not when you saidy, “Tomorrow, I'm going to start a new life to become the best version of myself,” and after somea few days or weeks, you stop because you are too lazy to go oncontinue.

"When you said," means it is something I, the reader, have literally said before. But to mean this saying in general, use "When you say"
Some subtleties, "after a few days," and "to continue" work better here

When I talk about a new life, I'm talking about every single day when you wake up and do these little things you plan to do, every day, even if you are too busy, too tired and do not have any motivation.

Because to successed, you need to makeput in more effort.

Success is a noun, succeed is a verb.
We say that we "put in" effort

You do not really need motivation, but discipline et, and for that you must do what you plan to without thinking (about anything else).

Two possibilities for the end of this sentence:
...do what you plan to without thinking = you do your tasks almost automatically, without needing to remind yourself to do them
...do what you plan to without thinking about anything else = you do your tasks without distractions (e.g., temptation to go watch TV instead)