Do 4 years old children NEED to go to school?

I am so confused. Here I am in Malaysia where most children start going to kindergarten at 5 years old. Yet where I came from (Singapore), most children start learning as early as 2 years old. I sent my son when he was 3 to a nursery last year. But this year due to financial instability and extreme time constraint, i decided to put his learning to a temporary halt. This however has caused a uneasiness for my mother as she's scared that her grandchild will not have good education. I feel so helpless and useless.

4 years of motherhood

In 2 months time, my first child will be 4 years old, while my second child will be into his 21st month of life. But I still could NOT say I enjoy motherhood. I really don't. But being in the motherhood trap also means that I could not and will not ever wish that they just disappear from my life because if that really happens, I'm afraid that i would either go out of mind or out of life. I just don't understand how people can go through life with so much chaos that children bring. Why can't I be a better mother?