HELP! Stuck at 580!

Hello experts, I am a non-native speaker. I have been studying for six months and have some problems with my progress so far. My CAT scores have been the following: MGMAT CAT 1: 580 (Q40 V30) MGMAT CAT 2: 640 (Q43 V34) MGMAT CAT 3: 580 (Q40 V31) MGMAT CAT 4: 590 (Q38 V34) MGMAT CAT 5: 570 (Q39 V30) ...