690 -->660 -->630 What do i DO ?

Guys, i have a problem and i need your help.

I started with the GMAT thinking i will do well in my first attempt but landed at a 690. I needed to get into the 700+ zone which is a psychological barrier for a Indian Male Engineer and took the exam 7 months later and got a 660. Disheartened, i tried analysing my mistakes (which i thought was more related to timing during the exam) and decided to give it a third shot. After 4 months of intense study and 10 mock tests later, i scored a 630 on my third attempt. I have been decently good in academics (scoring more than 90% in maths from school to engineering as well) and my verbal skills are not bad as well.

I cannot live with a score of 630 especially since it shows a downward trend. I took the first test 690 (Q49, V34) in Aug'13, second 660 (Q48, V33) in MAY'14 and third 630 (Q48, V28) in Mar'15. All three were sort of independent attempts since i spent lot of time between two attempts (due to personal and prof reasons)

Should i attempt the GMAT for the fourth time. I really want to get into the 700+ zone. Will my chances of admission be affected if i take the GMAT 4 times (thinking of schools like INSEAD, LBS, M7)