In bold are things are wrong or it is not what you would like to say... In blue are the things I couldn't understand so well. And in grey are the things I would suggest something different...

I'm not a teacher or so, but I'm trying to help as I can, alright?

So, let's go to your mistakes:

worthy to be finished => I guess you would like to say that it worths for you write every day even it's not that easy.

So, then I would say just "It is not easy, but worth it!", however you can also say, for example: "It is not easy, but is worth to make it" (or produce it, do it, write it).

 avoid burnout => This one I have no clue about the meaning. But this habit to write really often something can help you to improve your writing skills in another language, improve your vocabulary...

I'm tired because of working  => it is not wrong, but i would say " I'm tired because of MY work"

 "... and I don't have any energy to complete my writing, I write a sentence instead." => You've been repeating a lot the word "writing" and some times you can also use some words to make the links between the sentences. Maybe you could say here: "... and I don't have any energy to complete my text, then I write at least a sentence instead.

lose the momentum => there is an expression "waste time" for this meaning. You could say: " It is a little bit tricky, but I don't want to waste my time doing anything since I could be learning at least a bit of English."

Momentum is hard to be developed => I don't understand so much what you would like to say. So, I guess is " Life is short, we have to enjoy and manage better our time to improve ourselves as much as we can". 

In case I stop writing a day, I will stop writing next day. => I guess you would like to say: " In case I would stop to write one/some day, I would stop writing the next day as well."

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I hope I could help you a bit! Keep writing and improving your skills!

I Try To Write Something Every day

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I wasn't sure what you meant by "it's worthy to be finished" but I suppose you meant, "it's worth doing"

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I usually write about 100 to 150 words per day. It can help me to avoid burnout. Writing becomes my habit. Sometimes, I'm tired because of working, and I don't have any energy to complete my writing. I write a sentence instead. It is a little bit tricky, but I don't want to lose the momentum. Momentum is hard to be developed. In case I stop writing one a day, I will stop writing the next day. It really is a terrible thing.

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The answer is to write when you feel like it, not when you have to!