Hi! I´ve been learning english since I was 3 and I was terrible at first, but now its really easy for me, the best part.... I never EVER learned all those grammar rules, eventually they became natural.
My recommendation (this worked for me) watch movies you really like with subtitles first in you language and then in english, also play music you like with lyrics on screen. Try reading easy text
And most important!!... don´t try to remember the rules, just let go and practice as often as you can talking with others
Hope this helps you, It worked with me =) Have a nice day!