My life will change

Today I decided to make an important decision, I resigned from my job. When I decided to do it I was so afraid! But now I'm feel great, maybe this decision was wrong, maybe it was right! I hope I am going to be myself and now I am free!

Great - enjoy!

my life will change

Today I decided to do a made an important decision. , I decided to resign from my job. When I decided to do it, I'm so fear I was very afraid! But now I'm content with [or "confident in"] my decision. f fortunately , Maybe the decided decision is wrong-- , maybe it is right! I hope my decision will free me to express myself more.  I hope I am being true to myself. gonna be myself and I free in myself.  

I was not sure sure what you meant by the phrase: "But now I'm fortunately..."  My correction may not reflect your true intent.  

I think I understand what you are trying to say in the last sentence.  However, I took some liberties in suggesting changes. There are many possible ways to express those kinds of ideas.  

In parts, I am a little unclear on the proper verb tense to use.  Did you actually resign today, or did you only make the decision to resign (i.e. did you decide to resign on a future date)?  If you already resigned from your job, then I would make another change: "Maybe the decision was wrong--maybe it was right!  If you only made the decision to resign, but have not yet done so, I would keep this sentence in present tense.  Maybe other English speakers have a better explanation?

Hope that helps a little.