Hi Mehmet. I am a lifetime language learner, so I think you are doing well. You MUST practice every day. Reading is a good way to learn new vocabulary. So is watching movies, where you watch the subtitles in the Spanish language, and can pause the movie to check out the language.
What has really helped me is finding a local Spanish club, where you listen to, and speak Spanish. There may be one in your city.
Finally, I joined iTalki to improve my grammar, and I do this by having lots of Notebook entries. It has helped, although my progress is slow. You are much younger than I am, so I am sure you will progress more quickly. Best wishes!