GMAT Strategy

let my start by giving some background from my experience
with The GMAT
my first test was hideous and I ended up with 220 when i finished the test
however, since i didn't study anything that didn't bather me a lot
after that, I studied very hard for 3 months,6 hours per day
I re-toke the test again and my score was 400
but this time my score was really disappointing
another thing i would like to add, English isn't my first language and I thought maybe my problem is the language
my score in TOEFL ibt is 85
reading 17, speaking 23, writing 18, and listening 27
my cats score
MG cat 1 390 Q(27)v(12)
MG cat 2 460 Q(31)v(23)
MG cat 3 380 Q(28)v(10)
gmat prep 380 Q(27)v(16)

i didn't prepare a lot for the verbal sections all my concentration was in the Q
my question is, can i improve my score to be over 550 in 4 months ? ( i don't have job )
is my problem because of my English is weak?
sometime i need a complete minute just to understand the argument in CR
most wrong questions in Q are world problems especially in algebra translation
CR is the weakest part in V

Any advice would be very helpful