Some of my hairs stay short and don’t grow at all

But most of my hair doesn’t even grow for 2 years before falling out, I see some short hairs that fall out and they only grew for about 1-2 months?

All scalp hair cycles between a growth phase ~2-4 years for men and telogen (a sleep phase for hair which lasts up to 6 months). Short hairs that are seen in the balding area are probably miniaturized hairs that don’t grow well. Miniaturized hairs are often frozen in the anagen phase before they fall out and are lost forever.  This happens in many men.  You would know this as these hairs pull out easily. I am not recommending that you pull them out.  These hairs, left untreated, will die off sooner or later.